<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.3 20210610//EN" "JATS-journalpublishing1-3-mathml3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" article-type="systematic-review" dtd-version="1.3" xml:lang="EN">
<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Endocrinol.</journal-id>
<journal-title-group>
<journal-title>Frontiers in Endocrinology</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Endocrinol.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1664-2392</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.3389/fendo.2026.1736208</article-id>
<article-version article-version-type="Version of Record" vocab="NISO-RP-8-2008"/>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Systematic Review</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Clinical characteristics associated with somatic <italic>GNAS</italic> mutations in acromegaly: a systematic review and institutional experience</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name><surname>Dillon</surname><given-names>Brendan R.</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/3262413/overview"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="conceptualization" vocab-term-identifier="https://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="methodology" vocab-term-identifier="https://credit.niso.org/contributor-roles/methodology/">Methodology</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Formal analysis" vocab-term-identifier="https://credit.niso.org/contributor-roles/formal-analysis/">Formal analysis</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; original draft" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-original-draft/">Writing &#x2013; original draft</role>
</contrib>
<contrib contrib-type="author">
<name><surname>Ruddy</surname><given-names>Margaret</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/3314031/overview"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
</contrib>
<contrib contrib-type="author">
<name><surname>McQuade</surname><given-names>Emily C.</given-names></name>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="methodology" vocab-term-identifier="https://credit.niso.org/contributor-roles/methodology/">Methodology</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="conceptualization" vocab-term-identifier="https://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
</contrib>
<contrib contrib-type="author">
<name><surname>Shah</surname><given-names>Shruti N.</given-names></name>
<xref ref-type="aff" rid="aff3"><sup>3</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/1929187/overview"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
</contrib>
<contrib contrib-type="author">
<name><surname>Twi-Yeboah</surname><given-names>Alberta</given-names></name>
<xref ref-type="aff" rid="aff4"><sup>4</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Formal analysis" vocab-term-identifier="https://credit.niso.org/contributor-roles/formal-analysis/">Formal analysis</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
</contrib>
<contrib contrib-type="author">
<name><surname>Levinson</surname><given-names>Benjamin A.</given-names></name>
<xref ref-type="aff" rid="aff4"><sup>4</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/3269668/overview"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; original draft" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-original-draft/">Writing &#x2013; original draft</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Formal analysis" vocab-term-identifier="https://credit.niso.org/contributor-roles/formal-analysis/">Formal analysis</role>
</contrib>
<contrib contrib-type="author" corresp="yes">
<name><surname>Agrawal</surname><given-names>Nidhi</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>*</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/1976677/overview"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; original draft" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-original-draft/">Writing &#x2013; original draft</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Formal analysis" vocab-term-identifier="https://credit.niso.org/contributor-roles/formal-analysis/">Formal analysis</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="methodology" vocab-term-identifier="https://credit.niso.org/contributor-roles/methodology/">Methodology</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="supervision" vocab-term-identifier="https://credit.niso.org/contributor-roles/supervision/">Supervision</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="investigation" vocab-term-identifier="https://credit.niso.org/contributor-roles/investigation/">Investigation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="conceptualization" vocab-term-identifier="https://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="resources" vocab-term-identifier="https://credit.niso.org/contributor-roles/resources/">Resources</role>
</contrib>
</contrib-group>
<aff id="aff1"><label>1</label><institution>Holman Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Langone Health</institution>, <city>New York</city>, <state>NY</state>,&#xa0;<country country="us">United States</country></aff>
<aff id="aff2"><label>2</label><institution>Department of Medicine, New York University Langone Health</institution>, <city>New York</city>, <state>NY</state>,&#xa0;<country country="us">United States</country></aff>
<aff id="aff3"><label>3</label><institution>New York University Grossman School of Medicine</institution>, <city>New York</city>, <state>NY</state>,&#xa0;<country country="us">United States</country></aff>
<aff id="aff4"><label>4</label><institution>Division of Biostatistics, Department of Population Health, New York University Langone Health</institution>, <city>New York</city>, <state>NY</state>,&#xa0;<country country="us">United States</country></aff>
<author-notes>
<corresp id="c001"><label>*</label>Correspondence: Nidhi Agrawal, <email xlink:href="mailto:Nidhi.Agrawal@nyulangone.org">Nidhi.Agrawal@nyulangone.org</email></corresp>
</author-notes>
<pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-01-21">
<day>21</day>
<month>01</month>
<year>2026</year>
</pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2026</year>
</pub-date>
<volume>17</volume>
<elocation-id>1736208</elocation-id>
<history>
<date date-type="received">
<day>30</day>
<month>10</month>
<year>2025</year>
</date>
<date date-type="accepted">
<day>05</day>
<month>01</month>
<year>2026</year>
</date>
<date date-type="rev-recd">
<day>07</day>
<month>12</month>
<year>2025</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2026 Dillon, Ruddy, McQuade, Shah, Twi-Yeboah, Levinson and Agrawal.</copyright-statement>
<copyright-year>2026</copyright-year>
<copyright-holder>Dillon, Ruddy, McQuade, Shah, Twi-Yeboah, Levinson and Agrawal</copyright-holder>
<license>
<ali:license_ref start_date="2026-01-21">https://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open-access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License (CC BY)</ext-link>. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</license-p>
</license>
</permissions>
<abstract>
<sec>
<title>Introduction</title>
<p>Acromegaly is a rare, insidious disease associated with significant morbidity and mortality usually caused by a growth hormone (GH)-secreting pituitary tumor. Somatic mutations in <italic>GNAS</italic> are common in these tumors, yet their diagnostic, prognostic, and therapeutic implications are less clear.</p>
</sec>
<sec>
<title>Methods</title>
<p>We conducted a structured review of the literature and meta-analysis to investigate the association of <italic>GNAS</italic> mutation status with clinical characteristics and treatment outcomes in adult patients with acromegaly. This was complemented by an analysis comparing patients with acromegaly and identified tumor somatic <italic>GNAS</italic> mutations versus those without at our affiliated institution, NYU Langone Health.</p>
</sec>
<sec>
<title>Results</title>
<p>We identified 55 publications that met our inclusion criteria, all observational in nature and most retrospective in design. Twenty-two patients with acromegaly at our institution underwent pituitary tumor resection followed by tumor somatic mutation analysis from 2022 to 2024. The aggregate prevalence of somatic <italic>GNAS</italic> mutations in acromegaly was 38% in the systematic review, which was similar to the prevalence of 41% at our institution. While some studies in our review found patients with <italic>GNAS</italic> mutated tumors were older and more frequently male, most did not find this association. Whether these tumors demonstrate greater GH secretory capacity is unclear. There was greater consistency in findings that <italic>GNAS</italic>+ tumors are smaller and possibly less invasive. While greater GH suppression to acute octreotide treatment was frequently reported in patients with <italic>GNAS</italic>+ tumors, most studies that investigated the response to long-term somatostatin receptor ligand (SRL) therapy did not find an association between <italic>GNAS</italic> mutation presence and biochemical control. At our institution, patients with <italic>GNAS</italic>+ tumors were older at the time of surgery and most classified as mammosomatotroph adenomas on pathology.</p>
</sec>
<sec>
<title>Conclusions</title>
<p>Despite their high prevalence, <italic>GNAS</italic> mutations cannot reliably inform prognosis and treatment in acromegaly based on findings to date. Larger and prospective studies are needed exploring the frequency and intensity of preoperative symptoms and comorbidities, postoperative outcomes, and occurrence of prolactin co-secretion in <italic>GNAS</italic>+ tumors.</p>
</sec>
<sec>
<title>Systematic Review Registration</title>
<p><ext-link ext-link-type="uri" xlink:href="https://www.crd.york.ac.uk/prospero/">https://www.crd.york.ac.uk/prospero/</ext-link>, identifier CRD420251107763.</p>
</sec>
</abstract>
<kwd-group>
<kwd>acromegaly</kwd>
<kwd>clinical characteristics</kwd>
<kwd>GNAS</kwd>
<kwd>postoperative outcomes</kwd>
<kwd>somatotroph tumors</kwd>
</kwd-group>
<funding-group>
<funding-statement>The author(s) declared that financial support was received for this work and/or its publication. This research is supported in part by an NYU CTSA grant UL1 TR001445 from the National Center for Advancing Translational Sciences, National Institutes of Health. No other specific funding was used to carry out this research.</funding-statement>
</funding-group>
<counts>
<fig-count count="1"/>
<table-count count="4"/>
<equation-count count="9"/>
<ref-count count="91"/>
<page-count count="16"/>
<word-count count="7834"/>
</counts>
<custom-meta-group>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>Pituitary Endocrinology</meta-value>
</custom-meta>
</custom-meta-group>
</article-meta>
</front>
<body>
<sec id="s1" sec-type="intro">
<label>1</label>
<title>Introduction</title>
<p>Acromegaly is a rare, chronic condition marked by growth hormone (GH) hypersecretion most often due to a pituitary somatotroph adenoma with a wide range of clinical effects including physical, cardiovascular, pulmonary, metabolic, musculoskeletal, oncologic, and neuropsychiatric (<xref ref-type="bibr" rid="B1">1</xref>&#x2013;<xref ref-type="bibr" rid="B3">3</xref>). Diagnostic delay occurs in a majority of patients with a reported mean duration exceeding five years contributing to increased morbidity and mortality (<xref ref-type="bibr" rid="B4">4</xref>). While transsphenoidal resection is first-line therapy, surgical remission is achieved in only approximately 50% depending on tumor size and invasiveness as well as surgical center expertise (<xref ref-type="bibr" rid="B1">1</xref>, <xref ref-type="bibr" rid="B5">5</xref>, <xref ref-type="bibr" rid="B6">6</xref>). In the setting of persistent disease, medical therapy is needed targeting the somatotroph adenoma or antagonizing GH peripherally with the goal of achieving biochemical control (<xref ref-type="bibr" rid="B1">1</xref>, <xref ref-type="bibr" rid="B3">3</xref>, <xref ref-type="bibr" rid="B7">7</xref>), which is associated with normalization of mortality (<xref ref-type="bibr" rid="B8">8</xref>). Even when such control is achieved, symptoms and impaired quality of life frequently persist (<xref ref-type="bibr" rid="B9">9</xref>&#x2013;<xref ref-type="bibr" rid="B12">12</xref>). Ongoing follow up is required for all patients to monitor disease status and address comorbidities and complications (<xref ref-type="bibr" rid="B2">2</xref>, <xref ref-type="bibr" rid="B3">3</xref>, <xref ref-type="bibr" rid="B7">7</xref>).</p>
<p>Greater understanding of the molecular mechanisms underlying pituitary tumor pathogenesis has the potential to better inform prognosis and treatment planning (<xref ref-type="bibr" rid="B13">13</xref>). Somatic, gain-of-function mutations in <italic>GNAS</italic> encoding the stimulatory G-protein alpha subunit (Gs&#x3b1;) are well-established molecular drivers in acromegaly with a prevalence of approximately 40% (<xref ref-type="bibr" rid="B14">14</xref>). These missense point mutations occur at codon 201 or 227 in a heterogenous pattern and impair the intrinsic, inhibitory GTPase activity of Gs&#x3b1; resulting in constitutive activation of the cyclic adenosine monophosphate (cAMP) pathway necessary for GH secretion and cell proliferation (<xref ref-type="bibr" rid="B15">15</xref>, <xref ref-type="bibr" rid="B16">16</xref>). Studies investigating the clinical characteristics of <italic>GNAS</italic> mutations in acromegaly have yielded inconsistent results, although there is suggestion these tumors may be associated with older age at diagnosis, male sex, smaller size yet enhanced GH secretory ability, less invasion, densely granulated cytokeratin pattern, and greater response to somatostatin receptor ligand (SRL) therapy (<xref ref-type="bibr" rid="B17">17</xref>&#x2013;<xref ref-type="bibr" rid="B33">33</xref>).</p>
<p>A better understanding of the diagnostic and therapeutic implications of somatic <italic>GNAS</italic> mutations in acromegaly is needed. Our goals were to describe the clinical features of pituitary somatotroph tumors harboring these mutations through a systematic review of the literature with meta-analysis supplemented by an analysis comparing patients with acromegaly with and without tumor somatic <italic>GNAS</italic> mutations at our institution.</p>
</sec>
<sec id="s2">
<label>2</label>
<title>Methods</title>
<sec id="s2_1">
<label>2.1</label>
<title>Study protocol</title>
<p>This systematic review was conducted according to PRISMA 2020 statement guidelines and registered on PROSPERO (ID CRD420251107763). Our objectives were to investigate the association between <italic>GNAS</italic> mutation status and clinical features as well as treatment outcomes in adults with acromegaly.</p>
</sec>
<sec id="s2_2">
<label>2.2</label>
<title>Eligibility criteria</title>
<p>Studies were considered eligible for inclusion if they were published in a peer-reviewed journal, were written in English or with available English translation, and included adult patients with acromegaly and identified somatic <italic>GNAS</italic> mutations on surgical pathology molecular testing. Given the nature of the exposure, nonrandomized study types were included. Animal studies, studies with pediatric patients, case reports, reviews, book chapters, and conference proceedings were excluded.</p>
</sec>
<sec id="s2_3">
<label>2.3</label>
<title>Search strategy</title>
<p>Searches were conducted through Embase, PubMed, and Web of Science databases with no date restrictions. The following search terms were used in the search strategies: (&#x201c;acromegaly&#x201d; OR &#x201c;acromegalies&#x201d; OR &#x201c;acromegalic&#x201d; OR &#x201c;growth hormone-secreting pituitary adenoma&#x201d; OR &#x201c;growth hormone-secreting tumor&#x201d; OR &#x201c;somatotroph adenoma&#x201d; OR &#x201c;pituitary tumor&#x201d; OR &#x201c;growth hormone-secreting&#x201d; OR &#x201c;growth hormone-producing&#x201d; OR &#x201c;growth hormone hypersecretion&#x201d; OR &#x201c;GH-secreting&#x201d; OR &#x201c;GH-producing&#x201d; OR &#x201c;GH hypersecretion&#x201d;) AND (&#x201c;GNAS&#x201d; OR &#x201c;stimulatory G-protein alpha subunit&#x201d; OR &#x201c;Gs protein&#x201d; OR &#x201c;Gs alpha subunit&#x201d; OR &#x201c;G protein alpha subunit&#x201d; OR &#x201c;Gs alpha gene&#x201d; OR &#x201c;Gs alpha mutation&#x201d; OR &#x201c;G protein mutation&#x201d; OR &#x201c;Gsp&#x201d; OR &#x201c;Gps&#x201d;). <xref ref-type="fig" rid="f1"><bold>Figure&#xa0;1</bold></xref> illustrates the article selection process. After removal of duplicate publications, abstract screening, and review of the full-text for selected publications to assess for eligibility, 55 studies were included in the review. For two studies, data from two separate patient cohorts were reported, which we maintained in our data collection and analysis.</p>
<fig id="f1" position="float">
<label>Figure&#xa0;1</label>
<caption>
<p>Flow diagram for article selection.</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fendo-17-1736208-g001.tif">
<alt-text content-type="machine-generated">Flowchart depicting the study selection process for a review. Initially, 702 publications were identified from databases: Embase (302), PubMed (206), and Web of Science (194). After removing 363 duplicates, 339 abstracts were screened. Exclusions included unrelated objectives, review articles, and other criteria, leaving 73 full-text publications reviewed. 18 were excluded due to reasons like overlapping cohorts, resulting in 55 studies included in the review.</alt-text>
</graphic></fig>
</sec>
<sec id="s2_4">
<label>2.4</label>
<title>Data extraction</title>
<p>Four independent investigators screened the abstracts identified in the initial literature searches for relevance. Next, the full text of each selected article was reviewed to evaluate for inclusion. If two studies had overlapping patient cohorts, only one was included and was selected based on either a more complete reporting of clinical characteristics or a larger cohort size if both reported equally on clinical characteristics. Data extraction was completed by four independent investigators using Microsoft Excel. Variables of interest included demographics, symptoms, comorbidities, radiological features, pathological features, pre- and post-surgical hormone levels, and postsurgical outcomes. Age at diagnosis and age at surgery were considered equivalent for purposes of analysis. Hormone level values were converted to ng/mL for purposes of analysis.</p>
</sec>
<sec id="s2_5">
<label>2.5</label>
<title>NYU institutional experience</title>
<p>In the second component of this study, we investigated the clinical characteristics of adult patients with acromegaly with and without somatic <italic>GNAS</italic> mutations at our affiliated institution, NYU Langone Health in New York, NY. With assistance from the Department of Pathology Neuropathology Service, we identified all somatotroph adenomas that were resected and underwent genetic testing for somatic mutations from 2022 to 2024 following the advent of NYU Langone Genome PACT (Profiling of Actionable Cancer Targets) testing at our institution. NYU Langone Genome PACT is a diagnostic, qualitative, <italic>in vitro</italic> targeted next generation sequencing tumor profiling test that detects tumor gene alterations in a 607-gene panel. The electronic medical records of these patients were retrospectively reviewed and data collected related to the same variables of interest as the systematic review component. This component of the study was approved by the NYU Langone Health Institutional Review Board (protocol i24-00566) and determined to be exempt from full informed consent due to minimal risk.</p>
</sec>
<sec id="s2_6">
<label>2.6</label>
<title>Statistical analysis</title>
<p>SPSS software and R language software were used for statistical analysis.</p>
<sec id="s2_6_1">
<label>2.6.1</label>
<title>Meta-analysis</title>
<p>A mixed-effects meta-analysis was conducted to estimate the overall mean for continuous variables and the overall proportion for binary variables across studies. The random-effects model accounted for between-study heterogeneity by allowing the true effect sizes to vary across studies.</p>
<p>For continuous variables, the fixed effect was the study-specific mean, and the random effect was study.</p>
<p>If the mean was missing, we applied the following approximation methods for the mean in the order of priority, depending on the availability of other summary statistics, including median, minimum, maximum, first quartile (Q1), and third quartile (Q3):</p>
<p>1. Method A (<xref ref-type="bibr" rid="B34">34</xref>):</p>
<disp-formula>
<mml:math display="block" id="M1"><mml:mrow><mml:mtext>Mean</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mfrac><mml:mrow><mml:mtext>min</mml:mtext><mml:mo>+</mml:mo><mml:mn>2</mml:mn><mml:mo>*</mml:mo><mml:mtext>median</mml:mtext><mml:mo>+</mml:mo><mml:mtext>max</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:mfrac><mml:mtext>&#xa0;</mml:mtext></mml:mrow></mml:math>
</disp-formula>
<p>For small samples (<italic>n</italic> &lt; 25)</p>
<p>Method B (<xref ref-type="bibr" rid="B35">35</xref>, <xref ref-type="bibr" rid="B36">36</xref>):</p>
<disp-formula>
<mml:math display="block" id="M2"><mml:mrow><mml:mtext>Mean</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mfrac><mml:mrow><mml:mtext>Q</mml:mtext><mml:mn>1</mml:mn><mml:mo>+</mml:mo><mml:mtext>median</mml:mtext><mml:mo>+</mml:mo><mml:mtext>Q</mml:mtext><mml:mn>3</mml:mn></mml:mrow><mml:mn>3</mml:mn></mml:mfrac></mml:mrow></mml:math>
</disp-formula>
<p>2. Method C:</p>
<p>Mean &#x2248; Median</p>
<p>General statistical practice, used as fallback</p>
<p>If the standard deviation (SD) was missing, we used the following approximation methods in the order of priority, depending on the availability of other parameters, including median, minimum, maximum, Q1, Q3, and interquartile range (IQR):</p>
<p>Method A (<xref ref-type="bibr" rid="B34">34</xref>):</p>
<disp-formula>
<mml:math display="block" id="M3"><mml:mrow><mml:mtext>SD</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mo>&#x221a;</mml:mo><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mfrac><mml:mrow><mml:msup><mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext>min</mml:mtext><mml:mo>&#x2212;</mml:mo><mml:mtext>median</mml:mtext></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mn>2</mml:mn></mml:msup><mml:mo>+</mml:mo><mml:msup><mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext>max</mml:mtext><mml:mo>&#x2212;</mml:mo><mml:mtext>median</mml:mtext></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mn>2</mml:mn></mml:msup><mml:mo>+</mml:mo><mml:msup><mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mtext>max</mml:mtext><mml:mo>&#x2212;</mml:mo><mml:mtext>min</mml:mtext></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow><mml:mn>2</mml:mn></mml:msup><mml:mo>&#x200b;</mml:mo><mml:mo>&#x200b;</mml:mo></mml:mrow><mml:mn>3</mml:mn></mml:mfrac></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:math>
</disp-formula>
<p>1. Method B (<xref ref-type="bibr" rid="B34">34</xref>):</p>
<disp-formula>
<mml:math display="block" id="M4"><mml:mrow><mml:mtext>SD</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mfrac><mml:mrow><mml:mtext>max</mml:mtext><mml:mo>&#x2212;</mml:mo><mml:mtext>min</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:mfrac></mml:mrow></mml:math>
</disp-formula>
<p>For samples with <italic>n</italic><inline-formula>
<mml:math display="inline" id="im1"><mml:mo>&#x2264;</mml:mo></mml:math></inline-formula> 70</p>
<p>Method C (<xref ref-type="bibr" rid="B34">34</xref>, <xref ref-type="bibr" rid="B35">35</xref>):</p>
<disp-formula>
<mml:math display="block" id="M5"><mml:mrow><mml:mtext>SD</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mfrac><mml:mrow><mml:mtext>max</mml:mtext><mml:mo>&#x2212;</mml:mo><mml:mtext>min</mml:mtext></mml:mrow><mml:mn>6</mml:mn></mml:mfrac></mml:mrow></mml:math>
</disp-formula>
<p>For samples with <italic>n</italic><inline-formula>
<mml:math display="inline" id="im2"><mml:mo>&#x2265;</mml:mo></mml:math></inline-formula> 70</p>
<p>Method D (<xref ref-type="bibr" rid="B35">35</xref>, <xref ref-type="bibr" rid="B36">36</xref>):</p>
<disp-formula>
<mml:math display="block" id="M6"><mml:mrow><mml:mtext>SD</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mfrac><mml:mrow><mml:mtext>Q</mml:mtext><mml:mn>3</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mtext>Q</mml:mtext><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mn>1.35</mml:mn></mml:mrow></mml:mfrac><mml:mtext>&#xa0;</mml:mtext></mml:mrow></mml:math>
</disp-formula>
<p>Classical normal distribution property; popularized in meta-analysis literature</p>
<p>Method E (<xref ref-type="bibr" rid="B35">35</xref>, <xref ref-type="bibr" rid="B36">36</xref>):</p>
<disp-formula>
<mml:math display="block" id="M7"><mml:mrow><mml:mtext>SD</mml:mtext><mml:mo>&#x2248;</mml:mo><mml:mfrac><mml:mrow><mml:mtext>IQR</mml:mtext></mml:mrow><mml:mrow><mml:mn>1.35</mml:mn></mml:mrow></mml:mfrac></mml:mrow></mml:math>
</disp-formula>
<p>Classical normal distribution property; popularized in meta-analysis literature</p>
<p>For binary variables, proportions were transformed using the logit function to map values from the bounded [0, 1] scale to the entire real line, stabilizing variances and meeting model assumptions of normality and homoscedasticity. Specifically, the logit transformation was applied as:</p>
<disp-formula>
<mml:math display="block" id="M8"><mml:mrow><mml:mtext>logit</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mi>p</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:mi>log</mml:mi><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mfrac><mml:mi>p</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mi>p</mml:mi></mml:mrow></mml:mfrac></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:math>
</disp-formula>
<p>where <italic>p</italic> is the observed proportion.</p>
<p>Meta-analyses and mixed-effects modeling were then performed on the logit-transformed scale.</p>
<p>For interpretation and presentation, all model estimates and confidence intervals (CIs) were back-transformed to the original proportion scale using the inverse logit transformation:</p>
<disp-formula>
<mml:math display="block" id="M9"><mml:mrow><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mfrac><mml:mrow><mml:msup><mml:mi>e</mml:mi><mml:mrow><mml:mtext>logit</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mi>p</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>+</mml:mo><mml:msup><mml:mi>e</mml:mi><mml:mrow><mml:mtext>logit</mml:mtext><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mi>p</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:msup></mml:mrow></mml:mfrac></mml:mrow></mml:math>
</disp-formula>
<p>This approach allowed effect estimates and heterogeneity measures to be reported as proportions with corresponding 95% CIs.</p>
</sec>
<sec id="s2_6_2">
<label>2.6.2</label>
<title>NYU institutional experience</title>
<p>Descriptive statistics were calculated for the <italic>GNAS</italic>+ and <italic>GNAS</italic>- groups for each variable. Data were expressed as mean <inline-formula>
<mml:math display="inline" id="im3"><mml:mo>&#xb1;</mml:mo></mml:math></inline-formula>SD for continuous variables and <italic>n</italic> (%) for categorical variables. Continuous variables were compared using Student&#x2019;s <italic>t</italic>-test or Wilcoxon-Mann-Whitney test. Categorical variables were compared using Fisher&#x2019;s exact test. A <italic>p</italic> value&lt; 0.05 was considered significant.</p>
</sec>
</sec>
</sec>
<sec id="s3" sec-type="results">
<label>3</label>
<title>Results</title>
<sec id="s3_1">
<label>3.1</label>
<title>Types of studies</title>
<p>This systematic review included 55 studies with a total of 57 patient cohorts due to the two studies that reported two separate patient cohorts each. All studies were observational. The majority were retrospective (<italic>n</italic> = 41), while 14 studies were prospective in design. The cohorts were stratified by size as follows with most having 50 or fewer patients: <italic>n</italic><inline-formula>
<mml:math display="inline" id="im4"><mml:mo>&#x2264;</mml:mo></mml:math></inline-formula> 25 (20 cohorts), <italic>n</italic> = 26 &#x2013; 50 (20 cohorts), <italic>n</italic> = 51 &#x2013; 75 (10 cohorts), <italic>n</italic> = 76 &#x2013; 100 (3 cohorts), and <italic>n</italic><inline-formula>
<mml:math display="inline" id="im5"><mml:mo>&#x2265;</mml:mo></mml:math></inline-formula> 100 (4 cohorts). Year of publication ranged from 1990 to 2024. The geographic location of studies included Asia, Australia, Europe, North America, and South America.</p>
</sec>
<sec id="s3_2">
<label>3.2</label>
<title>Prevalence of <italic>GNAS</italic> mutations</title>
<p>The prevalence of somatic <italic>GNAS</italic> mutations was recorded for each patient cohort (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>). The total number of patients with acromegaly was 2, 540. The prevalence of <italic>GNAS</italic> mutations in acromegaly ranged from 4 &#x2013; 63% with an aggregate prevalence of 38%. Methods for somatic genetic testing varied among cohorts and included PCR-DNA direct sequencing analysis (<italic>k</italic> = 44), RT-PCR direct sequencing analysis (<italic>k</italic> = 5), PCR and oligonucleotide-specific hybridization (<italic>k</italic> = 3), PCR-single-strand conformation polymorphism analysis followed by sequencing (<italic>k</italic> = 2), targeted capture sequencing (<italic>k</italic> = 1), multiplexed next-generation sequencing (<italic>k</italic> = 1), and whole-exome sequencing (<italic>k</italic> = 1). For 847 patients with acromegaly and <italic>GNAS</italic>+ tumors, the location of the mutation was specified and occurred most commonly at codon Arg201 (84%) with the remaining occurring at codon Gln227. For 669 of these tumors, the specific mutation was specified with the following reported frequencies: Arg201Cys (75%), Gln227Leu (13%), Arg201His (6%), Arg201Ser (3%), Gln227Arg (3%), and Gln227Glu (&lt;0.01%). In two cases, mutations in both Arg201 and Gln227 were present. In one study, three previously unreported <italic>GNAS</italic> mutations (Gly49Arg, Ser111Asn, Ala249Asp) were found in the somatotroph adenoma from one patient (<xref ref-type="bibr" rid="B32">32</xref>). Most studies did not include testing for other somatic or germline gene mutations. In one cohort with 26 <italic>GNAS</italic>+ tumors, no somatic mutations in <italic>GHR</italic> were found (<xref ref-type="bibr" rid="B25">25</xref>). In one case, the presence of <italic>GNAS</italic> mutation was associated with allelic deletions of chromosome 11 (<xref ref-type="bibr" rid="B37">37</xref>). Among three cohorts with a total of 101 patients with <italic>GNAS</italic>+ tumors, co-occurring missense somatic mutations in <italic>AIP</italic> were detected in 4% (<xref ref-type="bibr" rid="B28">28</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B38">38</xref>). Among two cohorts with a total of 74 patients with <italic>GNAS</italic>+ tumors, no co-occurring somatic mutations in <italic>PRKACA</italic> were found (<xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B39">39</xref>). In one study with five <italic>GNAS</italic>+ tumors, no <italic>USP8</italic> somatic mutations were detected but polymorphisms in <italic>USP8</italic> at exon 1 and the 14-3&#x2013;3 binding domain were found in three cases (<xref ref-type="bibr" rid="B39">39</xref>). In one study involving targeted capture sequencing of 36 genes, among 69 <italic>GNAS</italic>+ tumors, there were three identified missense mutations in <italic>USP8</italic>, one missense mutation in <italic>GPR101</italic>, two missense mutations in <italic>PRKACB</italic>, one missense mutation in <italic>PRKAR1A</italic>, one missense mutation in <italic>ARRB1</italic>, two frameshift mutations in <italic>ARRB2</italic>, two missense mutations in <italic>SSTR5</italic>, and four missense mutations in <italic>MEN1</italic> (<xref ref-type="bibr" rid="B32">32</xref>). Finally, in one study with whole-exome sequencing, among 11 <italic>GNAS</italic>+ tumors, there was co-occurrence of mutations in other genes involved in cAMP signaling in two (<xref ref-type="bibr" rid="B39">39</xref>).</p>
<table-wrap id="T1" position="float">
<label>Table&#xa0;1</label>
<caption>
<p>Prevalence of <italic>GNAS</italic> mutations in somatotroph adenomas in included studies.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" align="left">Country</th>
<th valign="middle" align="left">Year</th>
<th valign="middle" align="left"><italic>n</italic></th>
<th valign="middle" align="left">Prevalence (%)</th>
<th valign="middle" align="left">Country</th>
<th valign="middle" align="left">Year</th>
<th valign="middle" align="left"><italic>n</italic></th>
<th valign="middle" align="left">Prevalence (%)</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="left">Australia</td>
<td valign="middle" align="left">1995 (<xref ref-type="bibr" rid="B84">84</xref>)</td>
<td valign="middle" align="left">13</td>
<td valign="middle" align="left">31</td>
<td valign="middle" rowspan="2" align="left">Germany, Italy</td>
<td valign="middle" align="left">2016 (<xref ref-type="bibr" rid="B39">39</xref>)</td>
<td valign="middle" align="left">31</td>
<td valign="middle" align="left">16</td>
</tr>
<tr>
<td valign="middle" rowspan="5" align="left">Brazil</td>
<td valign="middle" align="left">2009 (<xref ref-type="bibr" rid="B45">45</xref>)</td>
<td valign="middle" align="left">54</td>
<td valign="middle" align="left">15</td>
<td valign="middle" align="left">2016 (<xref ref-type="bibr" rid="B39">39</xref>)</td>
<td valign="middle" align="left">36</td>
<td valign="middle" align="left">31</td>
</tr>
<tr>
<td valign="middle" align="left">2011 (<xref ref-type="bibr" rid="B46">46</xref>)</td>
<td valign="middle" align="left">39</td>
<td valign="middle" align="left">10</td>
<td valign="middle" rowspan="10" align="left">Japan</td>
<td valign="middle" align="left">1993 (<xref ref-type="bibr" rid="B47">47</xref>)</td>
<td valign="middle" align="left">45</td>
<td valign="middle" align="left">4</td>
</tr>
<tr>
<td valign="middle" align="left">2018 (<xref ref-type="bibr" rid="B38">38</xref>)</td>
<td valign="middle" align="left">41</td>
<td valign="middle" align="left">27</td>
<td valign="middle" align="left">1993 (<xref ref-type="bibr" rid="B48">48</xref>)</td>
<td valign="middle" align="left">43</td>
<td valign="middle" align="left">9</td>
</tr>
<tr>
<td valign="middle" align="left">2021 (<xref ref-type="bibr" rid="B31">31</xref>)</td>
<td valign="middle" align="left">136</td>
<td valign="middle" align="left">40</td>
<td valign="middle" align="left">2003 (<xref ref-type="bibr" rid="B60">60</xref>)</td>
<td valign="middle" align="left">20</td>
<td valign="middle" align="left">55</td>
</tr>
<tr>
<td valign="middle" align="left">2022 (<xref ref-type="bibr" rid="B49">49</xref>)</td>
<td valign="middle" align="left">74</td>
<td valign="middle" align="left">40</td>
<td valign="middle" align="left">2006 (<xref ref-type="bibr" rid="B61">61</xref>)</td>
<td valign="middle" align="left">100</td>
<td valign="middle" align="left">53</td>
</tr>
<tr>
<td valign="middle" align="left">Canada</td>
<td valign="middle" align="left">1992 (<xref ref-type="bibr" rid="B85">85</xref>)</td>
<td valign="middle" align="left">15</td>
<td valign="middle" align="left">40</td>
<td valign="middle" align="left">2008 (<xref ref-type="bibr" rid="B62">62</xref>)</td>
<td valign="middle" align="left">20</td>
<td valign="middle" align="left">55</td>
</tr>
<tr>
<td valign="middle" rowspan="6" align="left">China</td>
<td valign="middle" align="left">1998 (<xref ref-type="bibr" rid="B40">40</xref>)</td>
<td valign="middle" align="left">40</td>
<td valign="middle" align="left">55</td>
<td valign="middle" align="left">2009 (<xref ref-type="bibr" rid="B63">63</xref>)</td>
<td valign="middle" align="left">56</td>
<td valign="middle" align="left">46</td>
</tr>
<tr>
<td valign="middle" align="left">2000 (<xref ref-type="bibr" rid="B55">55</xref>)</td>
<td valign="middle" align="left">18</td>
<td valign="middle" align="left">33</td>
<td valign="middle" align="left">2010 (<xref ref-type="bibr" rid="B43">43</xref>)</td>
<td valign="middle" align="left">43</td>
<td valign="middle" align="left">58</td>
</tr>
<tr>
<td valign="middle" align="left">2010 (<xref ref-type="bibr" rid="B64">64</xref>)</td>
<td valign="middle" align="left">43</td>
<td valign="middle" align="left">33</td>
<td valign="middle" align="left">2014 (<xref ref-type="bibr" rid="B41">41</xref>)</td>
<td valign="middle" align="left">67</td>
<td valign="middle" align="left">39</td>
</tr>
<tr>
<td valign="middle" align="left">2019 (<xref ref-type="bibr" rid="B29">29</xref>)</td>
<td valign="middle" align="left">25</td>
<td valign="middle" align="left">28</td>
<td valign="middle" align="left">2016 (<xref ref-type="bibr" rid="B27">27</xref>)</td>
<td valign="middle" align="left">61</td>
<td valign="middle" align="left">51</td>
</tr>
<tr>
<td valign="middle" align="left">2024 (<xref ref-type="bibr" rid="B33">33</xref>)</td>
<td valign="middle" align="left">97</td>
<td valign="middle" align="left">44</td>
<td valign="middle" align="left">2022 (<xref ref-type="bibr" rid="B32">32</xref>)</td>
<td valign="middle" align="left">121</td>
<td valign="middle" align="left">57</td>
</tr>
<tr>
<td valign="middle" align="left">2024 (<xref ref-type="bibr" rid="B69">69</xref>)</td>
<td valign="middle" align="left">44</td>
<td valign="middle" align="left">36</td>
<td valign="middle" align="left">Mexico</td>
<td valign="middle" align="left">2005 (<xref ref-type="bibr" rid="B22">22</xref>)</td>
<td valign="middle" align="left">58</td>
<td valign="middle" align="left">19</td>
</tr>
<tr>
<td valign="middle" align="left">Finland</td>
<td valign="middle" align="left">2017 (<xref ref-type="bibr" rid="B28">28</xref>)</td>
<td valign="middle" align="left">59</td>
<td valign="middle" align="left">36</td>
<td valign="middle" align="left">Norway</td>
<td valign="middle" align="left">2012 (<xref ref-type="bibr" rid="B44">44</xref>)</td>
<td valign="middle" align="left">74</td>
<td valign="middle" align="left">49</td>
</tr>
<tr>
<td valign="middle" rowspan="5" align="left">France</td>
<td valign="middle" align="left">1995 (<xref ref-type="bibr" rid="B65">65</xref>)</td>
<td valign="middle" align="left">15</td>
<td valign="middle" align="left">27</td>
<td valign="middle" rowspan="2" align="left">Poland</td>
<td valign="middle" align="left">2022 (<xref ref-type="bibr" rid="B68">68</xref>)</td>
<td valign="middle" align="left">134</td>
<td valign="middle" align="left">39</td>
</tr>
<tr>
<td valign="middle" align="left">1998 (<xref ref-type="bibr" rid="B19">19</xref>)</td>
<td valign="middle" align="left">30</td>
<td valign="middle" align="left">27</td>
<td valign="middle" align="left">2024 (<xref ref-type="bibr" rid="B86">86</xref>)</td>
<td valign="middle" align="left">48</td>
<td valign="middle" align="left">17</td>
</tr>
<tr>
<td valign="middle" align="left">2020 (<xref ref-type="bibr" rid="B67">67</xref>)</td>
<td valign="middle" align="left">53</td>
<td valign="middle" align="left">25</td>
<td valign="middle" rowspan="4" align="left">South Korea</td>
<td valign="middle" align="left">1996 (<xref ref-type="bibr" rid="B21">21</xref>)</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">43</td>
</tr>
<tr>
<td valign="middle" align="left">2021 (<xref ref-type="bibr" rid="B87">87</xref>)</td>
<td valign="middle" align="left">23</td>
<td valign="middle" align="left">39</td>
<td valign="middle" align="left">2001 (<xref ref-type="bibr" rid="B20">20</xref>)</td>
<td valign="middle" align="left">44</td>
<td valign="middle" align="left">16</td>
</tr>
<tr>
<td valign="middle" align="left">2021 (<xref ref-type="bibr" rid="B87">87</xref>)</td>
<td valign="middle" align="left">82</td>
<td valign="middle" align="left">23</td>
<td valign="middle" align="left">2004 (<xref ref-type="bibr" rid="B70">70</xref>)</td>
<td valign="middle" align="left">16</td>
<td valign="middle" align="left">63</td>
</tr>
<tr>
<td valign="middle" rowspan="2" align="left">Germany</td>
<td valign="middle" align="left">1993 (<xref ref-type="bibr" rid="B18">18</xref>)</td>
<td valign="middle" align="left">19</td>
<td valign="middle" align="left">42</td>
<td valign="middle" align="left">2021 (<xref ref-type="bibr" rid="B30">30</xref>)</td>
<td valign="middle" align="left">126</td>
<td valign="middle" align="left">60</td>
</tr>
<tr>
<td valign="middle" align="left">2013 (<xref ref-type="bibr" rid="B26">26</xref>)</td>
<td valign="middle" align="left">28</td>
<td valign="middle" align="left">36</td>
<td valign="middle" align="left">Spain</td>
<td valign="middle" align="left">2020 (<xref ref-type="bibr" rid="B42">42</xref>)</td>
<td valign="middle" align="left">50</td>
<td valign="middle" align="left">33</td>
</tr>
<tr>
<td valign="middle" rowspan="6" align="left">Italy</td>
<td valign="middle" align="left">1990 (<xref ref-type="bibr" rid="B88">88</xref>)</td>
<td valign="middle" align="left">18</td>
<td valign="middle" align="left">44</td>
<td valign="middle" align="left">Turkey</td>
<td valign="middle" align="left">2003 (<xref ref-type="bibr" rid="B89">89</xref>)</td>
<td valign="middle" align="left">7</td>
<td valign="middle" align="left">43</td>
</tr>
<tr>
<td valign="middle" align="left">1998 (<xref ref-type="bibr" rid="B90">90</xref>)</td>
<td valign="middle" align="left">26</td>
<td valign="middle" align="left">42</td>
<td valign="middle" rowspan="5" align="left">USA</td>
<td valign="middle" align="left">1990 (<xref ref-type="bibr" rid="B17">17</xref>)</td>
<td valign="middle" align="left">25</td>
<td valign="middle" align="left">40</td>
</tr>
<tr>
<td valign="middle" align="left">1998 (<xref ref-type="bibr" rid="B58">58</xref>)</td>
<td valign="middle" align="left">18</td>
<td valign="middle" align="left">36</td>
<td valign="middle" align="left">1992 (<xref ref-type="bibr" rid="B56">56</xref>)</td>
<td valign="middle" align="left">26</td>
<td valign="middle" align="left">35</td>
</tr>
<tr>
<td valign="middle" align="left">2001 (<xref ref-type="bibr" rid="B78">78</xref>)</td>
<td valign="middle" align="left">19</td>
<td valign="middle" align="left">37</td>
<td valign="middle" align="left">1995 (<xref ref-type="bibr" rid="B57">57</xref>)</td>
<td valign="middle" align="left">30</td>
<td valign="middle" align="left">33</td>
</tr>
<tr>
<td valign="middle" align="left">2001 (<xref ref-type="bibr" rid="B59">59</xref>)</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">38</td>
<td valign="middle" align="left">2007 (<xref ref-type="bibr" rid="B23">23</xref>)</td>
<td valign="middle" align="left">60</td>
<td valign="middle" align="left">40</td>
</tr>
<tr>
<td valign="middle" align="left">2003 (<xref ref-type="bibr" rid="B66">66</xref>)</td>
<td valign="middle" align="left">8</td>
<td valign="middle" align="left">38</td>
<td valign="middle" align="left">2017 (<xref ref-type="bibr" rid="B91">91</xref>)</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">29</td>
</tr>
<tr>
<td valign="middle" rowspan="2" align="left">Belgium, France, Italy</td>
<td valign="middle" rowspan="2" align="left">2013 (<xref ref-type="bibr" rid="B24">24</xref>)</td>
<td valign="middle" rowspan="2" align="left">39</td>
<td valign="middle" rowspan="2" align="left">36</td>
<td valign="middle" rowspan="2" align="left">UK</td>
<td valign="middle" align="left">1993 (<xref ref-type="bibr" rid="B37">37</xref>)</td>
<td valign="middle" align="left">11</td>
<td valign="middle" align="left">18</td>
</tr>
<tr>
<td valign="middle" align="left">2013 (<xref ref-type="bibr" rid="B25">25</xref>)</td>
<td valign="middle" align="left">49</td>
<td valign="middle" align="left">53</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p><italic>n</italic> total number of somatotroph adenomas with genetic testing for <italic>GNAS</italic> mutations.</p></fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec id="s3_3">
<label>3.3</label>
<title>Clinical characteristics of <italic>GNAS</italic> mutations in acromegaly</title>
<p>A comparison of <italic>GNAS</italic>+ versus <italic>GNAS</italic>- tumors with respect to clinical characteristics was reported in 38 studies. The reported associations of <italic>GNAS</italic> mutation with sex, age, basal hormone levels, tumor size, tumor invasion, tumor proliferation, postsurgical remission, and GH suppression with oral glucose tolerance testing (OGTT) and SRL treatment preoperatively and postoperatively are shown in <xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>. The overall means for continuous variables and overall proportions for binary variables for <italic>GNAS</italic>+ tumors across studies are displayed in <xref ref-type="table" rid="T3"><bold>Table&#xa0;3</bold></xref>.</p>
<table-wrap id="T2" position="float">
<label>Table&#xa0;2</label>
<caption>
<p>Association of <italic>GNAS</italic> mutation status with preoperative and postoperative clinical characteristics as reported by included studies.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" rowspan="2" align="center">Reference</th>
<th valign="middle" rowspan="2" align="center"><italic>n</italic>, total tested for <italic>GNAS</italic> mutation</th>
<th valign="middle" rowspan="2" align="center"><italic>n</italic>, <italic>GNAS+</italic></th>
<th valign="middle" colspan="13" align="center">Association of <italic>GNAS</italic> mutation with preoperative and postoperative clinical characteristics</th>
</tr>
<tr>
<th valign="middle" align="center">Sex</th>
<th valign="middle" align="center">Age</th>
<th valign="middle" align="center">Basal GH</th>
<th valign="middle" align="center">Basal IGF-1</th>
<th valign="middle" align="center">Basal PRL</th>
<th valign="middle" align="center">Tumor size</th>
<th valign="middle" align="center">Tumor invasion</th>
<th valign="middle" align="center">Pre-op OGTT response</th>
<th valign="middle" align="center">Pre-op SRL response</th>
<th valign="middle" align="center">Ki-67</th>
<th valign="middle" align="center">Post-op OGTT response</th>
<th valign="middle" align="center">Postsurgical remission</th>
<th valign="middle" align="center">Post-op SRL response</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B17">17</xref>)</td>
<td valign="middle" align="left">25</td>
<td valign="middle" align="left">10</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_1"><sup>a</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_2"><sup>b</sup></xref></td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_3"><sup>c</sup></xref></td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B56">56</xref>)</td>
<td valign="middle" align="left">26</td>
<td valign="middle" align="left">9</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B18">18</xref>)</td>
<td valign="middle" align="left">19</td>
<td valign="middle" align="left">8</td>
<td valign="middle" align="left">M&gt;F<xref ref-type="table-fn" rid="fnT2_4"><sup>d</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Lower<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">More</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B57">57</xref>)</td>
<td valign="middle" align="left">30</td>
<td valign="middle" align="left">10</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_6"><sup>f</sup></xref></td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B21">21</xref>)</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">9</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Older</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_7"><sup>g</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B19">19</xref>)</td>
<td valign="middle" align="left">30</td>
<td valign="middle" align="left">8</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_8"><sup>h</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Less<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Greater</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B58">58</xref>)</td>
<td valign="middle" align="left">18</td>
<td valign="middle" align="left">8</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B40">40</xref>)</td>
<td valign="middle" align="left">40</td>
<td valign="middle" align="left">22</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B55">55</xref>)</td>
<td valign="middle" align="left">18</td>
<td valign="middle" align="left">6</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Older<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Smaller<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B20">20</xref>)</td>
<td valign="middle" align="left">44</td>
<td valign="middle" align="left">7</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B59">59</xref>)</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">8</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B60">60</xref>)</td>
<td valign="middle" align="left">20</td>
<td valign="middle" align="left">11</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B70">70</xref>)</td>
<td valign="middle" align="left">16</td>
<td valign="middle" align="left">10</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B22">22</xref>)</td>
<td valign="middle" align="left">58</td>
<td valign="middle" align="left">11</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Lower<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_9"><sup>i</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B61">61</xref>)</td>
<td valign="middle" align="left">100</td>
<td valign="middle" align="left">53</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B23">23</xref>)</td>
<td valign="middle" align="left">60</td>
<td valign="middle" align="left">24</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Smaller<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B62">62</xref>)</td>
<td valign="middle" align="left">20</td>
<td valign="middle" align="left">11</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B45">45</xref>)</td>
<td valign="middle" align="left">54</td>
<td valign="middle" align="left">8</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Larger<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B63">63</xref>)</td>
<td valign="middle" align="left">56</td>
<td valign="middle" align="left">30</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B43">43</xref>)</td>
<td valign="middle" align="left">43</td>
<td valign="middle" align="left">25</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_10"><sup>j</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B64">64</xref>)</td>
<td valign="middle" align="left">43</td>
<td valign="middle" align="left">14</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B46">46</xref>)</td>
<td valign="middle" align="left">39</td>
<td valign="middle" align="left">4</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
</tbody>
<tbody>
<tr>
<th valign="middle" rowspan="2" align="left">Reference</th>
<th valign="middle" rowspan="2" align="left"><italic>n</italic>, total tested for <italic>GNAS</italic> mutation</th>
<th valign="middle" rowspan="2" align="left"><italic>n</italic>, <italic>GNAS+</italic></th>
<th valign="middle" colspan="13" align="left">Association of <italic>GNAS</italic> mutation with preoperative and postoperative clinical characteristics</th>
</tr>
<tr>
<th valign="middle" align="left">Sex</th>
<th valign="middle" align="left">Age</th>
<th valign="middle" align="left">Basal GH</th>
<th valign="middle" align="left">Basal IGF-1</th>
<th valign="middle" align="left">Basal PRL</th>
<th valign="middle" align="left">Tumor size</th>
<th valign="middle" align="left">Tumor invasion</th>
<th valign="middle" align="left">Pre-op OGTT response</th>
<th valign="middle" align="left">Pre-op SRL response</th>
<th valign="middle" align="left">Ki-67</th>
<th valign="middle" align="left">Post-op OGTT response</th>
<th valign="middle" align="left">Postsurgical remission</th>
<th valign="middle" align="left">Post-op SRL response</th>
</tr>
</tbody>
<tbody>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B44">44</xref>)</td>
<td valign="middle" align="left">74</td>
<td valign="middle" align="left">36</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_11"><sup>k</sup></xref></td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B25">25</xref>)</td>
<td valign="middle" align="left">49</td>
<td valign="middle" align="left">26</td>
<td valign="middle" align="left">M&gt;F<xref ref-type="table-fn" rid="fnT2_12"><sup>l</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B24">24</xref>)</td>
<td valign="middle" align="left">39</td>
<td valign="middle" align="left">14</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_13"><sup>m</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B41">41</xref>)</td>
<td valign="middle" align="left">67</td>
<td valign="middle" align="left">26</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B27">27</xref>)</td>
<td valign="middle" align="left">61</td>
<td valign="middle" align="left">31</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No<xref ref-type="table-fn" rid="fnT2_14"><sup>n</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Greater</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B28">28</xref>)</td>
<td valign="middle" align="left">59</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Less<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B38">38</xref>)</td>
<td valign="middle" align="left">41</td>
<td valign="middle" align="left">11</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B29">29</xref>)</td>
<td valign="middle" align="left">25</td>
<td valign="middle" align="left">7</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">Less</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Lower</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B67">67</xref>)</td>
<td valign="middle" align="left">53</td>
<td valign="middle" align="left">13</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B42">42</xref>)</td>
<td valign="middle" align="left">50</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B31">31</xref>)</td>
<td valign="middle" align="left">136</td>
<td valign="middle" align="left">54</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">Less</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B30">30</xref>)</td>
<td valign="middle" align="left">126</td>
<td valign="middle" align="left">75</td>
<td valign="middle" align="left">M&gt;F&#xb0;</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_16"><sup>p</sup></xref></td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B68">68</xref>)</td>
<td valign="middle" align="left">134</td>
<td valign="middle" align="left">52</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B32">32</xref>)</td>
<td valign="middle" align="left">121</td>
<td valign="middle" align="left">69</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">Less</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Greater<xref ref-type="table-fn" rid="fnT2_17"><sup>q</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B33">33</xref>)</td>
<td valign="middle" align="left">97</td>
<td valign="middle" align="left">43</td>
<td valign="middle" align="left">M&gt;F<xref ref-type="table-fn" rid="fnT2_18"><sup>r</sup></xref></td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">Higher<sup>e,j</sup></td>
<td valign="middle" align="left">Higher<xref ref-type="table-fn" rid="fnT2_5"><sup>e</sup></xref></td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Smaller</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Lower</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
</tr>
<tr>
<td valign="middle" align="left">(<xref ref-type="bibr" rid="B69">69</xref>)</td>
<td valign="middle" align="left">44</td>
<td valign="middle" align="left">16</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">Less</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">--</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">No</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>GH growth hormone, IGF-1 insulin-like growth factor 1, PRL prolactin, OGTT oral glucose tolerance test, SRL somatostatin receptor ligand.</p></fn>
<fn>
<p>--Not reported.</p></fn>
<fn id="fnT2_1"><label>a</label>
<p>GH level was lower in <italic>GNAS</italic>+, but there was no difference when controlled for tumor size.</p></fn>
<fn id="fnT2_2"><label>b</label>
<p>No difference when controlled for tumor size.</p></fn>
<fn id="fnT2_3"><label>c</label>
<p>Tumor invasion was greater in <italic>GNAS</italic>-, but there was no difference when controlled for tumor size.</p></fn>
<fn id="fnT2_4"><label>d</label>
<p>The prevalence of <italic>GNAS</italic> mutations was 67% in male patients and 18% in female patients.</p></fn>
<fn id="fnT2_5"><label>e</label>
<p>Trend reported but not statistically significant.</p></fn>
<fn id="fnT2_6"><label>f</label>
<p>Effect assessed <italic>in vitro</italic> via cell culture from surgical tissue.</p></fn>
<fn id="fnT2_7"><label>g</label>
<p>Of the 21 patients, 19 had no previous treatment for acromegaly, one had surgery 7 years prior, and one had radiation 5 years prior.</p></fn>
<fn id="fnT2_8"><label>h</label>
<p>When GH level per tumor diameter ratio considered, greater secretory activity noted in <italic>GNAS</italic>+.</p></fn>
<fn id="fnT2_9"><label>i</label>
<p>Microadenomas were more frequent in <italic>GNAS</italic>+, but this was not statistically significant.</p></fn>
<fn id="fnT2_10"><label>j</label>
<p>When GH level per tumor volume ratio considered, greater GH-producing index noted in <italic>GNAS</italic>+.</p></fn>
<fn id="fnT2_11"><label>k</label>
<p>No difference in GH reduction with SRL treatment was noted, but greater tumor reduction was seen in <italic>GNAS</italic>+.</p></fn>
<fn id="fnT2_12"><label>l</label>
<p>The prevalence of <italic>GNAS</italic> mutations was 70% in male patients and 37% in female patients.</p></fn>
<fn id="fnT2_14"><label>m</label>
<p>No difference in Ki-67 for untreated somatotroph adenomas. Ki-67 lower in <italic>GNAS</italic>+ tumors treated preoperatively with SRL therapy compared to treated <italic>GNAS</italic>- tumors.</p></fn>
<fn id="fnT2_13"><label>n</label>
<p><italic>GNAS</italic>+ tumors with higher GH levels corresponding to tumor size.</p></fn>
<fn>
<p>&#xb0;The prevalence of <italic>GNAS</italic> mutations was 76% in male patients and 48% in female patients.</p></fn>
<fn id="fnT2_16"><label>p</label>
<p><italic>GNAS</italic>+ tumors with lower nadir GH on immediate postoperative OGTT, but no difference noted on postoperative OGTT at 6 months.</p></fn>
<fn id="fnT2_17"><label>q</label>
<p>GH decrease by octreotide test greater in <italic>GNAS</italic>+ tumors but not significant, while GH decrease by preoperative SRL therapy significantly greater in <italic>GNAS</italic>+ tumors.</p></fn>
<fn id="fnT2_18"><label>r</label>
<p>The prevalence of <italic>GNAS</italic> mutations was 58% in male patients and 33% in female patients.</p></fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="T3" position="float">
<label>Table&#xa0;3</label>
<caption>
<p>Meta-analysis of the clinical characteristics of <italic>GNAS</italic>+ mutations in acromegaly.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" colspan="9" align="center">Continuous variables</th>
</tr>
<tr>
<th valign="middle" align="center">Variable</th>
<th valign="middle" align="center">Number of studies contributed</th>
<th valign="middle" align="center">Estimated overall mean</th>
<th valign="middle" align="center">Lower 95% CI</th>
<th valign="middle" align="center">Upper 95% CI</th>
<th valign="middle" align="center"><italic>p</italic>-value</th>
<th valign="middle" align="center">Significant at 5%</th>
<th valign="middle" align="center">Study random effect variance</th>
<th valign="middle" align="center">Heterogeneity score</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="left">Age (years)</td>
<td valign="middle" align="left">35</td>
<td valign="middle" align="left">45.9</td>
<td valign="middle" align="left">44.4</td>
<td valign="middle" align="left">47.4</td>
<td valign="middle" align="left">&lt; 0.0001</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">11.7</td>
<td valign="middle" align="left">64.6</td>
</tr>
<tr>
<td valign="middle" align="left">Basal GH (ng/mL)</td>
<td valign="middle" align="left">34</td>
<td valign="middle" align="left">31.3</td>
<td valign="middle" align="left">25.1</td>
<td valign="middle" align="left">37.6</td>
<td valign="middle" align="left">&lt; 0.0001</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">165.1</td>
<td valign="middle" align="left">83.6</td>
</tr>
<tr>
<td valign="middle" align="left">Basal IGF-1 (ng/mL)</td>
<td valign="middle" align="left">17</td>
<td valign="middle" align="left">824.7</td>
<td valign="middle" align="left">707.7</td>
<td valign="middle" align="left">941.8</td>
<td valign="middle" align="left">&lt; 0.0001</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">45517.3</td>
<td valign="middle" align="left">97.9</td>
</tr>
<tr>
<td valign="middle" align="left">Basal IGF-1 (xULN)</td>
<td valign="middle" align="left">5</td>
<td valign="middle" align="left">2.7</td>
<td valign="middle" align="left">1.5</td>
<td valign="middle" align="left">3.8</td>
<td valign="middle" align="left">0.003</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">0.6</td>
<td valign="middle" align="left">71.5</td>
</tr>
<tr>
<td valign="middle" align="left">Basal PRL (ng/mL)</td>
<td valign="middle" align="left">12</td>
<td valign="middle" align="left">23.7</td>
<td valign="middle" align="left">15.5</td>
<td valign="middle" align="left">31.8</td>
<td valign="middle" align="left">&lt; 0.0001</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">99.4</td>
<td valign="middle" align="left">79.7</td>
</tr>
<tr>
<td valign="middle" align="left">Tumor volume (cm<sup>3</sup>)</td>
<td valign="middle" align="left">7</td>
<td valign="middle" align="left">1.6</td>
<td valign="middle" align="left">1.0</td>
<td valign="middle" align="left">2.3</td>
<td valign="middle" align="left">0.0008</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">0.3</td>
<td valign="middle" align="left">69.9</td>
</tr>
<tr>
<td valign="middle" align="left">Tumor largest dimension (cm)</td>
<td valign="middle" align="left">21</td>
<td valign="middle" align="left">1.7</td>
<td valign="middle" align="left">1.5</td>
<td valign="middle" align="left">1.9</td>
<td valign="middle" align="left">&lt; 0.0001</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">0.1</td>
<td valign="middle" align="left">82.7</td>
</tr>
<tr>
<td valign="middle" align="left">Ki-67 (%)</td>
<td valign="middle" align="left">7</td>
<td valign="middle" align="left">1.3</td>
<td valign="middle" align="left">0.4</td>
<td valign="middle" align="left">2.2</td>
<td valign="middle" align="left">0.01</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">0.9</td>
<td valign="middle" align="left">98.2</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative GH (ng/mL)</td>
<td valign="middle" align="left">3</td>
<td valign="middle" align="left">3.4</td>
<td valign="middle" align="left">0</td>
<td valign="middle" align="left">25.2</td>
<td valign="middle" align="left">0.57</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">50.4</td>
<td valign="middle" align="left">0</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative IGF-1 (ng/mL)</td>
<td valign="middle" align="left">3</td>
<td valign="middle" align="left">250</td>
<td valign="middle" align="left">18.4</td>
<td valign="middle" align="left">481.7</td>
<td valign="middle" align="left">0.04</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">5581.7</td>
<td valign="middle" align="left">95.8</td>
</tr>
<tr>
<th valign="middle" colspan="9" align="center">Binary variables</th>
</tr>
<tr>
<th valign="middle" align="center">Variable</th>
<th valign="middle" align="center">Number of studies contributed</th>
<th valign="middle" align="center">Estimated overall proportion</th>
<th valign="middle" align="center">Lower 95% CI</th>
<th valign="middle" align="center">Upper 95% CI</th>
<th valign="middle" align="center"><italic>p</italic>-value</th>
<th valign="middle" align="center">Significant at 5%</th>
<th valign="middle" align="center">Study random effect variance</th>
<th valign="middle" align="center">Heterogeneity score</th>
</tr>
<tr>
<td valign="middle" align="left">Female sex (%)</td>
<td valign="middle" align="left">35</td>
<td valign="middle" align="left">51.4</td>
<td valign="middle" align="left">48.1</td>
<td valign="middle" align="left">54.8</td>
<td valign="middle" align="left">0.38</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">0</td>
<td valign="middle" align="left">0</td>
</tr>
<tr>
<td valign="middle" align="left">Macroadenoma (%)</td>
<td valign="middle" align="left">16</td>
<td valign="middle" align="left">78.3</td>
<td valign="middle" align="left">69.4</td>
<td valign="middle" align="left">85.1</td>
<td valign="middle" align="left">&lt; 0.0001</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">0.2</td>
<td valign="middle" align="left">36.3</td>
</tr>
<tr>
<td valign="middle" align="left">Cavernous sinus invasion (%)</td>
<td valign="middle" align="left">14</td>
<td valign="middle" align="left">25.2</td>
<td valign="middle" align="left">15.1</td>
<td valign="middle" align="left">38.8</td>
<td valign="middle" align="left">0.003</td>
<td valign="middle" align="left">Yes</td>
<td valign="middle" align="left">0.8</td>
<td valign="middle" align="left">71.6</td>
</tr>
<tr>
<td valign="middle" align="left">Densely granulated (%)</td>
<td valign="middle" align="left">5</td>
<td valign="middle" align="left">56.2</td>
<td valign="middle" align="left">31.3</td>
<td valign="middle" align="left">78.4</td>
<td valign="middle" align="left">0.54</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">0.5</td>
<td valign="middle" align="left">78.1</td>
</tr>
<tr>
<td valign="middle" align="left">Sparsely granulated (%)</td>
<td valign="middle" align="left">5</td>
<td valign="middle" align="left">36.2</td>
<td valign="middle" align="left">15.3</td>
<td valign="middle" align="left">64.1</td>
<td valign="middle" align="left">0.24</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">0.7</td>
<td valign="middle" align="left">83.6</td>
</tr>
<tr>
<td valign="middle" align="left">Mixed pattern granulation (%)</td>
<td valign="middle" align="left">2</td>
<td valign="middle" align="left">12.8</td>
<td valign="middle" align="left">1.4x10<sup>-5</sup></td>
<td valign="middle" align="left">100</td>
<td valign="middle" align="left">0.33</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">1.8</td>
<td valign="middle" align="left">74.9</td>
</tr>
<tr>
<td valign="middle" align="left">Surgical remission (%)</td>
<td valign="middle" align="left">7</td>
<td valign="middle" align="left">51.9</td>
<td valign="middle" align="left">29.2</td>
<td valign="middle" align="left">73.8</td>
<td valign="middle" align="left">0.85</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">0.8</td>
<td valign="middle" align="left">76.9</td>
</tr>
<tr>
<td valign="middle" align="left">Remission at last follow up (%)</td>
<td valign="middle" align="left">4</td>
<td valign="middle" align="left">53.2</td>
<td valign="middle" align="left">29.6</td>
<td valign="middle" align="left">75.4</td>
<td valign="middle" align="left">0.71</td>
<td valign="middle" align="left">No</td>
<td valign="middle" align="left">0.2</td>
<td valign="middle" align="left">33.3</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>CI, confidence interval; GH, growth hormone; IGF-1, insulin-like growth factor 1; PRL, prolactin; ULN, upper limit of normal.</p></fn>
</table-wrap-foot>
</table-wrap>
<sec id="s3_3_1">
<label>3.3.1</label>
<title>Demographics, preoperative symptoms and comorbidities, preoperative hormone levels</title>
<p>Only a limited number of studies (<italic>n</italic> = 8) explicitly reported on preoperative symptoms and signs, comorbidities, or disease duration. Most did not find a difference between patients with and without <italic>GNAS</italic> mutations (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B20">20</xref>, <xref ref-type="bibr" rid="B22">22</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B40">40</xref>&#x2013;<xref ref-type="bibr" rid="B42">42</xref>), although one study reported increased diagnostic delay and frequency of vision impairment without increased visual field deficits in patients with <italic>GNAS</italic> mutations (<xref ref-type="bibr" rid="B33">33</xref>).</p>
<p>With respect to sex, 30 studies reported the association with <italic>GNAS</italic> mutation status. <italic>GNAS</italic>+ tumors were more common in male patients in four of these studies with the remainder finding no association. Using data from 35 studies, the estimated overall proportion female was 51.4% for patients with <italic>GNAS</italic>+ tumors (95% CI [48.1 &#x2013; 54.8%], <italic>p</italic> = 0.38, <italic>I</italic><sup>2</sup> = 0%).</p>
<p>With respect to age, 32 studies reported the association with <italic>GNAS</italic> mutation status with all but one finding no significant difference. Using data from 35 studies, the estimated overall mean age was 45.9 years for patients with <italic>GNAS</italic>+ tumors (95% CI [44.4 &#x2013; 47.4 years], <italic>p</italic> &lt; 0.0001, <italic>I</italic><sup>2</sup> = 65%).</p>
<p>In 31 studies, the association between <italic>GNAS</italic> mutation status and basal GH level was reported with most finding no association. While six found a trend of higher GH level with <italic>GNAS</italic>+ tumors, the difference was only significant in one study (<xref ref-type="bibr" rid="B29">29</xref>). However, four studies did note a higher secretory capacity in <italic>GNAS</italic>+ tumors when accounting for tumor size (<xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B33">33</xref>, <xref ref-type="bibr" rid="B43">43</xref>). Using data from 34 studies, the estimated overall mean basal GH level was 31.3 ng/mL for patients with <italic>GNAS</italic>+ tumors (95% CI [25.1 &#x2013; 37.6 ng/mL], <italic>p</italic> &lt; 0.0001, <italic>I</italic><sup>2</sup> = 84%). In 23 studies, the association between <italic>GNAS</italic> mutation status and basal insulin-like growth factor 1 (IGF-1) level was reported with most finding no association. Five studies reported a higher IGF-1 level with <italic>GNAS</italic>+ tumors with this difference being significant in three. Patients with <italic>GNAS</italic>+ tumors had an estimated overall mean basal IGF-1 level of 824.7 ng/mL (95% CI [707.7 &#x2013; 941.8 ng/mL], <italic>p</italic> &lt; 0.0001, <italic>I</italic><sup>2</sup> = 99%) using data from 17 studies and an estimated mean IGF-1 level expressed as a multiple of the upper limit of normal (ULN) of 2.7 (95% CI [1.5 &#x2013; 3.8], <italic>p</italic> = 0.003, <italic>I</italic><sup>2</sup> = 72%) using data from five studies. Fewer studies (<italic>n</italic> = 16) reported the association between <italic>GNAS</italic> mutation status and basal prolactin level with 13 finding no association and three finding significantly higher prolactin levels with <italic>GNAS</italic>+ tumors. Using data from 12 studies, the overall mean basal prolactin level was 23.7 ng/mL (95% CI [15.5 &#x2013; 31.8 ng/mL], <italic>p</italic> &lt; 0.0001, <italic>I</italic><sup>2</sup> = 80%) for patients with GNAS+ tumors. With respect to GH reduction with OGTT, a greater response was demonstrated in patients with <italic>GNAS</italic>+ tumors in three out of eight studies. Preoperative response to SRL therapy either by acute octreotide testing or more sustained treatment was assessed in 14 studies with most finding a trend of greater response in the <italic>GNAS</italic>+ group, which was significant in seven studies.</p>
</sec>
<sec id="s3_3_2">
<label>3.3.2</label>
<title>Radiological features</title>
<p>The association between <italic>GNAS</italic> mutation status and tumor size was reported in 33 studies. When compared to <italic>GNAS</italic>- tumors, <italic>GNAS</italic>+ tumors were significantly smaller in nine studies. Tumors with <italic>GNAS</italic>+ tumors had an estimated overall mean tumor volume of 1.6 cm<sup>3</sup> (95% CI [1.0 - 2.3 cm<sup>3</sup>], <italic>p</italic> = 0.0008, <italic>I</italic><sup>2</sup> = 70%) using data from seven studies and an estimated overall mean tumor diameter of 1.7 cm (95% CI [1.5 - 1.9 cm], <italic>p</italic> &lt; 0.0001, <italic>I</italic><sup>2</sup> = 83%) using data from 21 studies. Using data from 16 studies, the estimated overall proportion of <italic>GNAS</italic>+ tumors classified as macroadenomas was 78.3% (95% CI [69.4 &#x2013; 85.1%], <italic>p</italic> &lt; 0.0001, <italic>I</italic><sup>2</sup> = 36%). The association between <italic>GNAS</italic> mutation status and tumor invasion was reported in 23 studies with significantly less invasion in 4, more invasion in 1, and no difference in 18. Using data from 14 studies, the estimated overall proportion of <italic>GNAS</italic>+ tumors with cavernous sinus invasion as assessed on preoperative magnetic resonance imaging (MRI) was 25.2% (95% CI [15.1 - 38.8%], <italic>p</italic> = 0.003, <italic>I</italic><sup>2</sup> = 72%).</p>
</sec>
<sec id="s3_3_3">
<label>3.3.3</label>
<title>Pathological features</title>
<p>The association between <italic>GNAS</italic> mutation status and tumor proliferation as assessed by Ki-67 proliferation index was reported by 12 studies with lower Ki-67 reported in two studies and no association in the remainder. Using data from seven studies, the estimated overall mean Ki67 of <italic>GNAS</italic>+ tumors was 1.3% (95% CI [0.4 &#x2013; 2.2%], <italic>p</italic> = 0.01, <italic>I</italic><sup>2</sup> = 98%). Using data from three studies, the estimated overall proportion with Ki67&lt; 3% was 74.4% (95% CI [60.2 &#x2013; 84.7%], <italic>p</italic> &lt; 0.02, <italic>I</italic><sup>2</sup> = 0%).</p>
<p>Granulation pattern data was reported in six studies. <italic>GNAS</italic> mutations were more common in densely granulated adenomas compared to sparsely granulated adenomas in one study (<xref ref-type="bibr" rid="B26">26</xref>), but no significant difference in granulation pattern between <italic>GNAS</italic>+ and <italic>GNAS</italic>- was reported in four studies (<xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B41">41</xref>, <xref ref-type="bibr" rid="B44">44</xref>). Using data from five studies, in <italic>GNAS</italic>+ tumors, the estimated overall proportion of densely granulated adenomas was 56.2% (95% CI [31.3 &#x2013; 78.4%], <italic>p</italic> = 0.54, <italic>I</italic><sup>2</sup> = 78%), sparsely granulated adenomas was 36.2% (95% CI [15.3 &#x2013; 64.1%], <italic>p</italic> = 0.24, <italic>I</italic><sup>2</sup> = 84%), and mixed pattern adenomas was 12.8% (95% CI [1.4x10<sup>-5</sup> &#x2013; 100%], <italic>p</italic> = 0.33, <italic>I</italic><sup>2</sup> = 75%).</p>
</sec>
<sec id="s3_3_4">
<label>3.3.4</label>
<title>Postoperative outcomes</title>
<p>Compared to preoperative data, data on postoperative outcomes was comparatively less reported, and there was greater heterogeneity with respect to measures used and timing. The association between <italic>GNAS</italic> mutation status and postsurgical remission was reported in 10 studies with greater remission for <italic>GNAS</italic>+ tumors found in two. Using data from seven studies, the estimated overall proportion of patients with <italic>GNAS</italic>+ tumors with postsurgical remission was 51.9% (95% CI [29.2 &#x2013; 73.8%], <italic>p</italic> = 0.85, <italic>I</italic><sup>2</sup> = 77%). Using data from three studies, patients with <italic>GNAS</italic>+ tumors had an estimated overall mean postoperative GH level of 3.4 ng/mL (95% CI [0 &#x2013; 25.2 ng/mL], <italic>p</italic> = 0.57, <italic>I</italic><sup>2</sup> = 0%) and mean postoperative IGF-1 level of 250.0 ng/mL (95% CI [18.4 &#x2013; 481.7 ng/mL], <italic>p</italic> = 0.04, <italic>I</italic><sup>2</sup> = 96%).</p>
</sec>
</sec>
<sec id="s3_4">
<label>3.4</label>
<title>NYU institutional experience</title>
<p>A total of 22 patients with acromegaly underwent transsphenoidal resection at NYU Langone Health followed by tumor somatic mutation genetic testing from 2022 to 2024. Somatic, activating <italic>GNAS</italic> mutations were identified in 9 out of 22 patients (41%). The identified mutations were Arg201Cys in five patients and Gln227Leu in four patients. The clinical characteristics grouped by <italic>GNAS</italic> mutation status are displayed in <xref ref-type="table" rid="T4"><bold>Table&#xa0;4</bold></xref>. Patients with <italic>GNAS</italic>+ tumors were older at the time of surgery compared to patients with <italic>GNAS</italic>- tumors with respective mean ages of 59.6 and 39.2 years (<italic>p</italic> = 0.003). There were no significant differences in preoperative symptoms or comorbidities in patients with <italic>GNAS</italic>+ versus <italic>GNAS</italic>- tumors. Preoperative GH, IGF-1, and prolactin levels were higher in patients with <italic>GNAS</italic>+ tumors, but these differences were not statistically significant. Additionally, tumor volume and largest dimension did not differ. Postoperative GH level was lower in patients with <italic>GNAS</italic>+ tumors (mean 2.7 versus 3.9 ng/mL, <italic>p</italic> = 0.01). Postoperative prolactin level was also lower (mean 4.7 versus 10.3 ng/mL, <italic>p</italic> = 0.006). Postoperative IGF-1 was lower in the <italic>GNAS</italic>+ group but this difference was not significant. Similarly, postoperative decreases in GH and IGF-1 were greater in the <italic>GNAS</italic>+ group but not significant. With respect to pathological diagnosis, seven out of nine <italic>GNAS</italic>+ tumors demonstrated dual GH and prolactin staining with six mammosomatotroph adenomas (MSA) and one mixed somatotroph-lactotroph adenoma (MSLA). Tumor DNA methylation profiling revealed a class of pituitary adenoma, STH densely granulated, group B in all <italic>GNAS</italic>+ tumors. Molecular testing demonstrated <italic>NTRK3</italic>-<italic>SH3GL3</italic> gene fusion in one <italic>GNAS</italic>+ tumor. No other somatic tumor mutations were found. Germline genetic testing was obtained in four patients with <italic>GNAS</italic>+ tumors and two patients with <italic>GNAS</italic>- tumors. Heterozygous mutations in <italic>CHEK2</italic> and <italic>APC</italic> were found in one patient with a <italic>GNAS</italic>- tumor. No pathogenic germline variants were detected in the other five patients.</p>
<table-wrap id="T4" position="float">
<label>Table&#xa0;4</label>
<caption>
<p>Clinical characteristics of patients with acromegaly with and without tumor somatic <italic>GNAS</italic> mutations.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" align="left">Clinical characteristics and postsurgical outcomes</th>
<th valign="middle" align="center"><italic>GNAS</italic>+ (<italic>n</italic> = 9)</th>
<th valign="middle" align="center"><italic>GNAS</italic>- (<italic>n</italic> = 13)</th>
<th valign="middle" align="center"><italic>p</italic>-value</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="left">Sex (Male/Female)</td>
<td valign="middle" align="left">4/5</td>
<td valign="middle" align="left">7/6</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Age at surgery (years)</td>
<td valign="middle" align="left">59.6 &#xb1; 14.0</td>
<td valign="middle" align="left">39.2 &#xb1; 10.7</td>
<td valign="middle" align="left">0.003</td>
</tr>
<tr>
<td valign="middle" align="left">Headache</td>
<td valign="middle" align="left">33%</td>
<td valign="middle" align="left">69%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Acromegalic facial features</td>
<td valign="middle" align="left">89%</td>
<td valign="middle" align="left">85%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Arthralgias</td>
<td valign="middle" align="left">78%</td>
<td valign="middle" align="left">54%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Dysglycemia</td>
<td valign="middle" align="left">67%</td>
<td valign="middle" align="left">54%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Hyperlipidemia</td>
<td valign="middle" align="left">78%</td>
<td valign="middle" align="left">62%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Hypertension</td>
<td valign="middle" align="left">67%</td>
<td valign="middle" align="left">54%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Obstructive sleep apnea</td>
<td valign="middle" align="left">56%</td>
<td valign="middle" align="left">38%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Carpal tunnel syndrome</td>
<td valign="middle" align="left">33%</td>
<td valign="middle" align="left">23%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Thyroid nodule(s)</td>
<td valign="middle" align="left">78%</td>
<td valign="middle" align="left">46%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Colon polyp(s)</td>
<td valign="middle" align="left">56%</td>
<td valign="middle" align="left">46%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Visual problems</td>
<td valign="middle" align="left">33%</td>
<td valign="middle" align="left">23%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Visual field deficit</td>
<td valign="middle" align="left">0%</td>
<td valign="middle" align="left">8%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Abnormal periods</td>
<td valign="middle" align="left">11%</td>
<td valign="middle" align="left">8%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Sexual dysfunction</td>
<td valign="middle" align="left">11%</td>
<td valign="middle" align="left">23%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Preoperative GH (ng/mL)</td>
<td valign="middle" align="left">34.3 &#xb1; 29.2</td>
<td valign="middle" align="left">22.6 &#xb1; 40.5, 1 ND</td>
<td valign="middle" align="left">0.08</td>
</tr>
<tr>
<td valign="middle" align="left">Preoperative IGF-1 (xULN)</td>
<td valign="middle" align="left">2.8 &#xb1; 0.7</td>
<td valign="middle" align="left">2.3 &#xb1; 0.7, 1 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Preoperative PRL (ng/mL)</td>
<td valign="middle" align="left">34.3 &#xb1; 33.1</td>
<td valign="middle" align="left">20.4 &#xb1; 15.2, 1 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Tumor volume (cm<sup>3</sup>)</td>
<td valign="middle" align="left">2.8 &#xb1; 2.4</td>
<td valign="middle" align="left">4.5 &#xb1; 7.3</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Tumor largest dimension (cm)</td>
<td valign="middle" align="left">2.0 &#xb1; 0.5</td>
<td valign="middle" align="left">2.0 &#xb1; 0.9</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Cavernous sinus invasion</td>
<td valign="middle" align="left">44%</td>
<td valign="middle" align="left">46%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Suprasellar extension</td>
<td valign="middle" align="left">44%</td>
<td valign="middle" align="left">46%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Bone invasion</td>
<td valign="middle" align="left">11%</td>
<td valign="middle" align="left">8%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Optic chiasm compression</td>
<td valign="middle" align="left">11%</td>
<td valign="middle" align="left">15%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">MRI T2 hyperintensity</td>
<td valign="middle" align="left">22%</td>
<td valign="middle" align="left">8%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Preoperative SRL therapy</td>
<td valign="middle" align="left">22%</td>
<td valign="middle" align="left">0%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Ki-67&lt; 3%</td>
<td valign="middle" align="left">78%</td>
<td valign="middle" align="left">54%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Pathological diagnosis<break/>PSA<break/>MSA<break/>MSLA<break/>Plurihormonal</td>
<td valign="middle" align="left">22%<break/>67%<break/>11%<break/>0%</td>
<td valign="middle" align="left">46%<break/>8%<break/>8%<break/>38%</td>
<td valign="middle" align="left">0.01</td>
</tr>
<tr>
<td valign="middle" align="left">Methylation class<break/>PITAD STH DNS A<break/>PITAD STH DNS B<break/>PITAD STH SPA</td>
<td valign="middle" align="left">0%<break/>100%<break/>0%</td>
<td valign="middle" align="left">54%<break/>8%<break/>38%</td>
<td valign="middle" align="left">&lt;0.0001</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative day 1 GH (ng/mL)</td>
<td valign="middle" align="left">1.2 &#xb1; 0.9, 1 ND</td>
<td valign="middle" align="left">5.3 &#xb1; 11.6, 2 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative GH (ng/mL)</td>
<td valign="middle" align="left">2.7 &#xb1; 1.5</td>
<td valign="middle" align="left">4.0 &#xb1; 11.4, 1 ND</td>
<td valign="middle" align="left">0.01</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative GH delta (ng/mL)</td>
<td valign="middle" align="left">-31.6 &#xb1; 28.8</td>
<td valign="middle" align="left">-18.6 +/- 29.4</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative IGF-1 (xULN)</td>
<td valign="middle" align="left">0.9 &#xb1; 0.3</td>
<td valign="middle" align="left">1.2 &#xb1; 0.8, 2 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative IGF-1 delta (ng/mL)</td>
<td valign="middle" align="left">-1647.1 &#xb1; 3059.2, 1 ND</td>
<td valign="middle" align="left">-393.5 &#xb1; 218.1, 3 ND</td>
<td valign="middle" align="left">0.07</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative PRL (ng/mL)</td>
<td valign="middle" align="left">4.7 &#xb1; 1.8, 1 ND</td>
<td valign="middle" align="left">10.3 &#xb1; 7.1, 2 ND</td>
<td valign="middle" align="left">0.006</td>
</tr>
<tr>
<td valign="middle" align="left">Postsurgical remission</td>
<td valign="middle" align="left">57%, 2 ND</td>
<td valign="middle" align="left">64%, 2 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative hypogonadism</td>
<td valign="middle" align="left">50%, 3 ND</td>
<td valign="middle" align="left">44%, 4 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative hypothyroidism</td>
<td valign="middle" align="left">13%, 1 ND</td>
<td valign="middle" align="left">18%, 2 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative adrenal insufficiency</td>
<td valign="middle" align="left">22%</td>
<td valign="middle" align="left">25%, 1 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative hypopituitarism</td>
<td valign="middle" align="left">11%</td>
<td valign="middle" align="left">0%, 1 ND</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative permanent AVP deficiency</td>
<td valign="middle" align="left">0%</td>
<td valign="middle" align="left">8%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative radiotherapy</td>
<td valign="middle" align="left">0%</td>
<td valign="middle" align="left">8%</td>
<td valign="middle" align="left">NS</td>
</tr>
<tr>
<td valign="middle" align="left">Postoperative SRL therapy</td>
<td valign="middle" align="left">22%</td>
<td valign="middle" align="left">31%</td>
<td valign="middle" align="left">NS</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>AVP arginine vasopressin, GH, growth hormone; IGF-1, insulin-like growth factor 1; MRI, magnetic resonance imaging; MSA, mammosomatotroph adenoma; MSLA, mixed somatotroph-lactotroph adenoma; ND, patients with missing data; NS, not significant; PITAD STH DNS A, pituitary adenoma STH densely granulated group A; PITAD STH DNS B, pituitary adenoma STH densely granulated group B; PITAD STH SPA, pituitary adenoma STH sparsely granulated; PRL, prolactin; PSA, pure somatotroph adenoma; SRL, somatostatin receptor ligand; ULN, upper limit of normal.</p></fn>
</table-wrap-foot>
</table-wrap>
</sec>
</sec>
<sec id="s4" sec-type="discussion">
<label>4</label>
<title>Discussion</title>
<p>We investigated the clinical characteristics of patients with acromegaly due to somatotroph adenomas harboring somatic, activating <italic>GNAS</italic> mutations through a structured review of the literature and comparison of patients with and without <italic>GNAS</italic> mutations at our institution.</p>
<p>Our findings confirm current understanding regarding the prevalence of <italic>GNAS</italic> mutations in acromegaly with an aggregate prevalence of 38% from the systematic review and 41% at our institution. In this systematic review, the included patient cohorts spanned five continents. With respect to differences by country, some earlier Brazilian and Japanese studies reported lower prevalence rates (<xref ref-type="bibr" rid="B45">45</xref>&#x2013;<xref ref-type="bibr" rid="B48">48</xref>); however, larger and more recent studies are not suggestive of a difference between these two countries and others (<xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B41">41</xref>, <xref ref-type="bibr" rid="B49">49</xref>). Somatic, activating <italic>GNAS</italic> mutations in somatotroph adenomas have been characterized as heterozygous, missense mutations occurring most frequently at Arg201 and less frequently at Gln227, which are most often identified via targeted gene sequencing (<xref ref-type="bibr" rid="B14">14</xref>). Whole genome and exome sequencing studies of GH-secreting adenomas have demonstrated <italic>GNAS</italic> mutation prevalence rates of 25 &#x2013; 54% (<xref ref-type="bibr" rid="B39">39</xref>, <xref ref-type="bibr" rid="B50">50</xref>&#x2013;<xref ref-type="bibr" rid="B53">53</xref>). Regarding the variability in the reported prevalence rates of <italic>GNAS</italic> mutations in acromegaly among the included studies in this systematic review which span a time period over 30 years, it is likely that use of different sequencing technologies and evolution in techniques over time partly account for this variation. Additionally, a majority of the studies focused their sequencing of <italic>GNAS</italic> at codons 201 and 227 within exons 8 and 9, respectively, and did not include testing for other somatic tumor mutations. Somatic variants in genes encoding G protein-coupled receptors (GPCRs) and proteins involved in cAMP or calcium signaling in patients with acromegaly with <italic>GNAS</italic>+ tumors have been identified (<xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B39">39</xref>). Future investigation is needed to better understand the role that novel <italic>GNAS</italic> variants and co-existing variants in other genes may play in the pathogenesis of acromegaly. For instance, emerging data have identified unique genetic variants that may influence the tumor microenvironment through immune cell activation and infiltration and thereby contribute to differences in disease phenotype (<xref ref-type="bibr" rid="B54">54</xref>).</p>
<p>While the prevalence of somatic <italic>GNAS</italic> mutations in acromegaly is relatively well established, the diagnostic, prognostic, and therapeutic implications are less certain. In this systematic review, a limited number of studies reported data for preoperative symptoms and signs, comorbidities, or disease duration, and most found no difference between patients with and without <italic>GNAS</italic>+ tumors (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B20">20</xref>, <xref ref-type="bibr" rid="B22">22</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B40">40</xref>&#x2013;<xref ref-type="bibr" rid="B42">42</xref>). However, one study found <italic>GNAS</italic>+ tumors were associated with a significantly longer diagnostic delay (<xref ref-type="bibr" rid="B33">33</xref>). Unlike most studies in the review, we found patients with <italic>GNAS</italic>+ tumors were significantly older at the time of surgery than patients with <italic>GNAS</italic>- tumors in our institution&#x2019;s cohort. It is possible diagnostic delay led to this finding, although data regarding occurrence of first comorbidity and time of diagnosis were not recorded. Additionally, we found no difference in the frequencies of symptoms, signs, and comorbidities in patients with and without <italic>GNAS</italic> tumor mutations. Similar to most studies in the review, we found no association between <italic>GNAS</italic> mutation status and sex.</p>
<p>It has been suggested that somatotroph adenomas with <italic>GNAS</italic> mutations are smaller yet demonstrate enhanced GH secretion related to constitutive activation of the cAMP pathway normally induced by stimulation of the growth hormone-releasing hormone (GHRH) receptor (<xref ref-type="bibr" rid="B29">29</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B33">33</xref>, <xref ref-type="bibr" rid="B43">43</xref>). In our review, while some studies reported a trend of higher GH levels in patients with <italic>GNAS</italic>+ tumors (<xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B45">45</xref>, <xref ref-type="bibr" rid="B55">55</xref>), most reported no association (<xref ref-type="bibr" rid="B17">17</xref>, <xref ref-type="bibr" rid="B20">20</xref>, <xref ref-type="bibr" rid="B21">21</xref>, <xref ref-type="bibr" rid="B24">24</xref>, <xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B28">28</xref>, <xref ref-type="bibr" rid="B30">30</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B40">40</xref>, <xref ref-type="bibr" rid="B41">41</xref>, <xref ref-type="bibr" rid="B56">56</xref>&#x2013;<xref ref-type="bibr" rid="B64">64</xref>) with only one reporting a significantly higher GH level (<xref ref-type="bibr" rid="B29">29</xref>), only four reporting significantly higher GH levels when accounting for tumor size (<xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B33">33</xref>, <xref ref-type="bibr" rid="B43">43</xref>), and two reporting a trend of lower GH levels (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B22">22</xref>). With respect to IGF-1 levels in patients with <italic>GNAS</italic>+ tumors compared to those with <italic>GNAS</italic>- tumors, most reported similar levels (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B22">22</xref>, <xref ref-type="bibr" rid="B24">24</xref>, <xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B28">28</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B41">41</xref>, <xref ref-type="bibr" rid="B56">56</xref>, <xref ref-type="bibr" rid="B59">59</xref>&#x2013;<xref ref-type="bibr" rid="B64">64</xref>) with three reporting significantly higher levels (<xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B29">29</xref>, <xref ref-type="bibr" rid="B30">30</xref>) and two reporting only a trend of higher levels (<xref ref-type="bibr" rid="B33">33</xref>, <xref ref-type="bibr" rid="B45">45</xref>). In our institution&#x2019;s cohort, GH and IGF-1 levels were higher in patients with <italic>GNAS</italic>+ tumors, but these differences were not significant. Activation of the cAMP pathway with its downstream effects, such as phosphorylation of transcription factor cAMP response element-binding protein (CREB), is considered a key component in somatotroph tumorigenesis regardless of <italic>GNAS</italic> mutation status (<xref ref-type="bibr" rid="B53">53</xref>, <xref ref-type="bibr" rid="B65">65</xref>, <xref ref-type="bibr" rid="B66">66</xref>). Lower expression of <italic>PDE4D</italic> encoding a phosphodiesterase (PDE) enzyme involved in hydrolysis and deactivation of cAMP was demonstrated in somatotroph adenomas compared to gonadotroph and lactotroph adenomas (<xref ref-type="bibr" rid="B53">53</xref>). However, <italic>GNAS</italic>+ and <italic>GNAS</italic>- tumors do not necessarily differ in cAMP levels which has been attributed to significantly greater PDE activity in mutated tumors (<xref ref-type="bibr" rid="B58">58</xref>). Thus, while <italic>GNAS</italic> mutations may result in greater GH secretion, increased PDE activity and other factors may attenuate this effect resulting in no difference in GH levels.</p>
<p>Regarding tumor size, several studies including those with some of the largest sample sizes found <italic>GNAS</italic>+ tumors were significantly smaller than <italic>GNAS</italic>- tumors (<xref ref-type="bibr" rid="B17">17</xref>, <xref ref-type="bibr" rid="B20">20</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B29">29</xref>, <xref ref-type="bibr" rid="B31">31</xref>&#x2013;<xref ref-type="bibr" rid="B33">33</xref>, <xref ref-type="bibr" rid="B43">43</xref>, <xref ref-type="bibr" rid="B59">59</xref>), although many found no association (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B21">21</xref>, <xref ref-type="bibr" rid="B22">22</xref>, <xref ref-type="bibr" rid="B24">24</xref>, <xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B28">28</xref>, <xref ref-type="bibr" rid="B30">30</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B40">40</xref>&#x2013;<xref ref-type="bibr" rid="B42">42</xref>, <xref ref-type="bibr" rid="B44">44</xref>, <xref ref-type="bibr" rid="B56">56</xref>&#x2013;<xref ref-type="bibr" rid="B58">58</xref>, <xref ref-type="bibr" rid="B60">60</xref>, <xref ref-type="bibr" rid="B62">62</xref>, <xref ref-type="bibr" rid="B64">64</xref>, <xref ref-type="bibr" rid="B67">67</xref>, <xref ref-type="bibr" rid="B68">68</xref>). In one study, combination of data with earlier series led to a finding of significantly smaller size among <italic>GNAS</italic>+ tumors with suspicion that earlier studies were likely limited in their ability to find an effect due to small sample sizes (<xref ref-type="bibr" rid="B23">23</xref>). In our cohort, <italic>GNAS</italic>+ tumor volume was lower but not significantly different with the ability to find an effect possibly limited by our relatively small sample size. With respect to tumor invasion, most initial studies did not find an association with <italic>GNAS</italic> mutation status (<xref ref-type="bibr" rid="B20">20</xref>, <xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B40">40</xref>, <xref ref-type="bibr" rid="B55">55</xref>, <xref ref-type="bibr" rid="B56">56</xref>, <xref ref-type="bibr" rid="B64">64</xref>), while some more recent studies found <italic>GNAS</italic>+ tumors were less invasive (<xref ref-type="bibr" rid="B29">29</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B51">51</xref>, <xref ref-type="bibr" rid="B69">69</xref>). In our cohort, there was no difference in cavernous sinus invasion with respect to <italic>GNAS</italic> mutation status. Demonstration of increased expression of cell-cycle checkpoints p53 and p21<sup>Wif1/Cip1</sup> in somatotroph adenomas led to the hypothesis that this finding may contribute to restricted growth and expansion in <italic>GNAS</italic>+ tumors (<xref ref-type="bibr" rid="B53">53</xref>). Additionally, increased expression of the large non-coding RNA and tumor suppressor <italic>MEG3</italic> in <italic>GNAS</italic>+ GH-secreting tumors has been implicated in limiting invasion via inactivation of the Wnt/&#x3b2;-catenin signaling pathway (<xref ref-type="bibr" rid="B29">29</xref>, <xref ref-type="bibr" rid="B69">69</xref>). If <italic>GNAS</italic>+ tumors are associated with reduced tumor proliferation, Ki67 index is an inconsistent marker of this based on the studies in our review, as several studies found no association (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B28">28</xref>, <xref ref-type="bibr" rid="B30">30</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B43">43</xref>, <xref ref-type="bibr" rid="B63">63</xref>), and two found Ki67 indices were lower in mutated tumors (<xref ref-type="bibr" rid="B29">29</xref>, <xref ref-type="bibr" rid="B33">33</xref>). In our cohort, a greater proportion of <italic>GNAS</italic>+ tumors demonstrated Ki67 indices less than 3%, but the difference was not significant. If <italic>GNAS</italic>+ tumors are smaller and less invasive, then postsurgical remission may be higher in this subset of tumors. In the limited number of studies reporting postsurgical data, most did not find a difference (<xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B20">20</xref>, <xref ref-type="bibr" rid="B22">22</xref>, <xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B33">33</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B69">69</xref>). In the two studies reporting higher postsurgical remission in <italic>GNAS</italic>+ tumors, the two groups did not differ in terms of tumor size and invasion (<xref ref-type="bibr" rid="B30">30</xref>, <xref ref-type="bibr" rid="B40">40</xref>), which suggests other factors modulate this possible association. In our small cohort, rates of surgical remission did not differ among patients with versus without <italic>GNAS</italic> mutations. Future investigation with greater standardization of postoperative measures is needed to confirm if prognostic differences exist with respect to surgical resection.</p>
<p>At a molecular level, SRL therapy targets the cAMP pathway which is constitutively activated in somatotroph adenomas with <italic>GNAS</italic> mutations (<xref ref-type="bibr" rid="B53">53</xref>). Several studies have investigated the association of <italic>GNAS</italic> mutation status and SRL treatment response with both acute and long-term administration (<xref ref-type="bibr" rid="B19">19</xref>&#x2013;<xref ref-type="bibr" rid="B21">21</xref>, <xref ref-type="bibr" rid="B23">23</xref>&#x2013;<xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B27">27</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B41">41</xref>&#x2013;<xref ref-type="bibr" rid="B44">44</xref>, <xref ref-type="bibr" rid="B46">46</xref>, <xref ref-type="bibr" rid="B61">61</xref>, <xref ref-type="bibr" rid="B63">63</xref>, <xref ref-type="bibr" rid="B69">69</xref>, <xref ref-type="bibr" rid="B70">70</xref>). Across these studies, findings are inconsistent regarding whether <italic>GNAS</italic> mutations are associated with a more favorable response. A meta-analysis of eight studies with 310 patients who underwent acute octreotide suppression testing demonstrated more pronounced GH suppression in patients with <italic>GNAS</italic>+ tumors (weighted mean difference 9.08%, 95% CI [2.73-15.42], <italic>p</italic> = 0.005) (<xref ref-type="bibr" rid="B71">71</xref>). However, response to acute octreotide treatment does not necessarily portend long-term efficacy in acromegaly (<xref ref-type="bibr" rid="B7">7</xref>, <xref ref-type="bibr" rid="B72">72</xref>&#x2013;<xref ref-type="bibr" rid="B74">74</xref>). Most studies that have evaluated postoperative biochemical control with SRL therapy in the setting of residual disease have found no difference related to the presence of a somatic <italic>GNAS</italic> mutation (<xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B38">38</xref>, <xref ref-type="bibr" rid="B42">42</xref>, <xref ref-type="bibr" rid="B44">44</xref>, <xref ref-type="bibr" rid="B69">69</xref>). The findings of our review support the recently published consensus statement from the 15<sup>th</sup> Acromegaly Consensus Conference with discretionary recommendation against using the presence of <italic>GNAS</italic> mutations to predict SRL treatment response and guide selection of medical therapy either preoperatively or following surgical resection with inadequate disease control (<xref ref-type="bibr" rid="B7">7</xref>). However, greater quality evidence through larger and prospective studies would be beneficial. IGF-1 dynamics during standard-dose and high-dose or high-frequency first-generation SRL therapy can predict long-term biochemical response and inform therapeutic decisions (<xref ref-type="bibr" rid="B75">75</xref>). Future investigation should explore the effect of <italic>GNAS</italic> mutation status, if any, in predicting response to different modes of SRL therapy as assessed by IGF-1 dynamics.</p>
<p>Densely granulated cytokeratin pattern and high somatostatin receptor 2 (SSTR2) expression are recommended factors for predicting postoperative SRL response (<xref ref-type="bibr" rid="B7">7</xref>). In this review, most studies that evaluated granulation pattern did not find a difference between tumors with and without <italic>GNAS</italic> mutations (<xref ref-type="bibr" rid="B25">25</xref>, <xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B41">41</xref>, <xref ref-type="bibr" rid="B44">44</xref>), while in one study, <italic>GNAS</italic> mutations were more common in densely granulated adenomas (<xref ref-type="bibr" rid="B26">26</xref>). Findings with respect to SSTR2 expression in <italic>GNAS</italic>+ tumors are mixed with some studies reporting higher expression (<xref ref-type="bibr" rid="B46">46</xref>, <xref ref-type="bibr" rid="B76">76</xref>, <xref ref-type="bibr" rid="B77">77</xref>) and others reporting no difference (<xref ref-type="bibr" rid="B31">31</xref>, <xref ref-type="bibr" rid="B70">70</xref>, <xref ref-type="bibr" rid="B78">78</xref>, <xref ref-type="bibr" rid="B79">79</xref>). In one series, the presence of <italic>GNAS</italic> mutation was associated with increased frequency of plasma-membrane-dominant staining of SSTR2A (<xref ref-type="bibr" rid="B63">63</xref>). However, while GH reduction with acute octreotide administration was greater in the patients with <italic>GNAS</italic>+ tumors, this difference did not reach statistical significance. Interestingly, somatostatin receptor 5 (SSTR5) expression was found to be lower in <italic>GNAS</italic>+ tumors in a large cohort study (<xref ref-type="bibr" rid="B31">31</xref>). Further investigation is needed with respect to postoperative outcomes and SRL response in tumors with <italic>GNAS</italic>+ tumors in association with granulation pattern and SSTR2/5 expression.</p>
<p>A notable finding in our cohort of patients with acromegaly is the high proportion of <italic>GNAS</italic>+ tumors with dual GH- and prolactin-staining immunohistochemistry (IHC) with the majority being classified as mammosomatotroph adenomas. While <italic>GNAS</italic> mutations occur in GH and prolactin co-secreting adenomas, prior studies have not found a significant difference in prolactin staining or histological diagnosis between tumors with and without <italic>GNAS</italic> mutations (<xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B43">43</xref>, <xref ref-type="bibr" rid="B56">56</xref>, <xref ref-type="bibr" rid="B68">68</xref>), and one found less prolactin staining in the <italic>GNAS</italic>+ group (<xref ref-type="bibr" rid="B21">21</xref>). With regards to possible hypersecretion, higher basal prolactin levels have been found in some cohorts of <italic>GNAS</italic>+ tumors (<xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B28">28</xref>, <xref ref-type="bibr" rid="B32">32</xref>, <xref ref-type="bibr" rid="B56">56</xref>). In our cohort, preoperative prolactin levels were higher but not significantly different in patients with <italic>GNAS</italic>+ tumors. Approximately 25% of GH-secreting adenomas demonstrate prolactin staining (<xref ref-type="bibr" rid="B80">80</xref>). Proper histological classification of these tumors may have prognostic implications, as MSAs have been associated with smaller size, less invasion, and greater total gross resection, while MSLAs the inverse with greater hyperprolactinemia (<xref ref-type="bibr" rid="B81">81</xref>&#x2013;<xref ref-type="bibr" rid="B83">83</xref>). Future investigation should explore the prevalence of <italic>GNAS</italic> mutations in dual GH- and prolactin-staining tumors and the association with clinical features, including those associated with prolactin hypersecretion, and postoperative outcomes.</p>
<p>Our findings must be interpreted in the context of our study&#x2019;s limitations. First, all of the studies included in our review are observational in nature and most retrospective in design, thereby increasing the risk of bias and confounding factors. Most study samples were small to moderate in size, which limits generalizability due to possible selection bias and the ability to detect effects. For example, the introduction of somatic tumor mutation testing at our institution allowed for retrospective analysis of patients with and without <italic>GNAS</italic> mutations, but incorporation of this testing into clinical care is not uniform and there may be unique factors related to the decision to pursue analysis, such as preoperative features, radiographic evidence of invasiveness, and intraoperative findings. Additionally, the results of our meta-analysis for the clinical characteristics of <italic>GNAS</italic>+ tumors are limited by the variation in and evolution of hormone assays over time as well as variation in the units used requiring conversion. Furthermore, there was variability with respect to the methods and timing of postoperative assessment as well as proposed criteria for biochemical control and remission. Finally, interpretation of the pooled outcomes from the meta-analysis is limited when heterogeneity is high.</p>
<p>In conclusion, our systematic review and institutional experience confirms the prevalence of somatic <italic>GNAS</italic> mutations in acromegaly. At our institution, we found patients with <italic>GNAS</italic>+ tumors were significantly older, had lower postoperative growth hormone and prolactin levels, and were most likely to have a tumor pathology diagnosis of dual GH- and prolactin-staining adenoma. These tumors may be smaller yet demonstrate enhanced secretory ability with less invasion. Additional investigation is needed to better understand how these mutations are associated with the frequency and intensity of preoperative symptoms and comorbidities as well as postoperative outcomes. It is unclear if <italic>GNAS</italic> mutations predict long-term SRL treatment efficacy in the setting of residual disease. The possible association between <italic>GNAS</italic> mutation and GH and prolactin co-secreting adenomas should be explored.</p>
</sec>
</body>
<back>
<sec id="s5" sec-type="data-availability">
<title>Data availability statement</title>
<p>The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.</p></sec>
<sec id="s6" sec-type="author-contributions">
<title>Author contributions</title>
<p>BD: Investigation, Conceptualization, Methodology, Writing &#x2013; review &amp; editing, Formal Analysis, Data curation, Writing &#x2013; original draft. MR: Investigation, Writing &#x2013; review &amp; editing. EM: Methodology, Investigation, Writing &#x2013; review &amp; editing, Conceptualization. SS: Investigation, Writing &#x2013; review &amp; editing. AT: Data curation, Formal Analysis, Writing &#x2013; review &amp; editing. BL: Data curation, Writing &#x2013; review &amp; editing, Writing &#x2013; original draft, Formal Analysis. NA: Writing &#x2013; original draft, Writing &#x2013; review &amp; editing, Formal Analysis, Methodology, Supervision, Investigation, Data curation, Conceptualization, Resources.</p></sec>
<ack>
<title>Acknowledgments</title>
<p>We thank Drs. Sarra Belakhoua, Christopher M. William, and David Zagzag from the Neuropathology Service of the NYU Langone Department of Pathology for their assistance in identifying relevant cases of resected somatotroph adenomas that underwent somatic genetic testing. We thank Richard C. McGowan, MLS, Associate Curator from the Medical Library at NYU Grossman School of Medicine for his guidance and assistance with conducting the database searches for the systematic review component.</p>
</ack>
<sec id="s8" sec-type="COI-statement">
<title>Conflict of interest</title>
<p>NA is on the advisory board for Xeris, Amryt, Camurus, Crinetics, and Novo Nordisk and serves as a principal investigator on research trials for Amryt, Recordati, Ascendis, and Novo Nordisk.</p>
<p>The remaining authors declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p></sec>
<sec id="s9" sec-type="ai-statement">
<title>Generative AI statement</title>
<p>The author(s) declared that generative AI was not used in the creation of this manuscript.</p>
<p>Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.</p></sec>
<sec id="s10" sec-type="disclaimer">
<title>Publisher&#x2019;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p></sec>
<ref-list>
<title>References</title>
<ref id="B1">
<label>1</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Katznelson</surname> <given-names>L</given-names></name>
<name><surname>Laws</surname> <given-names>ER</given-names></name>
<name><surname>Melmed</surname> <given-names>S</given-names></name>
<name><surname>Molitch</surname> <given-names>ME</given-names></name>
<name><surname>Murad</surname> <given-names>MH</given-names></name>
<name><surname>Utz</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Acromegaly: an Endocrine Society clinical practice guideline</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>2014</year>) <volume>99</volume>:<page-range>3933&#x2013;51</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jc.2014-2700</pub-id>, PMID: <pub-id pub-id-type="pmid">25356808</pub-id>
</mixed-citation>
</ref>
<ref id="B2">
<label>2</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Fleseriu</surname> <given-names>M</given-names></name>
<name><surname>Biller</surname> <given-names>BMK</given-names></name>
<name><surname>Freda</surname> <given-names>PU</given-names></name>
<name><surname>Gadelha</surname> <given-names>MR</given-names></name>
<name><surname>Giustina</surname> <given-names>A</given-names></name>
<name><surname>Katznelson</surname> <given-names>L</given-names></name>
<etal/>
</person-group>. 
<article-title>A Pituitary Society update to acromegaly management guidelines</article-title>. <source>Pituitary</source>. (<year>2021</year>) <volume>24</volume>:<fpage>1</fpage>&#x2013;<lpage>13</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-020-01091-7</pub-id>, PMID: <pub-id pub-id-type="pmid">33079318</pub-id>
</mixed-citation>
</ref>
<ref id="B3">
<label>3</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Giustina</surname> <given-names>A</given-names></name>
<name><surname>Biermasz</surname> <given-names>N</given-names></name>
<name><surname>Casanueva</surname> <given-names>FF</given-names></name>
<name><surname>Fleseriu</surname> <given-names>M</given-names></name>
<name><surname>Mortini</surname> <given-names>P</given-names></name>
<name><surname>Strasburger</surname> <given-names>C</given-names></name>
<etal/>
</person-group>. 
<article-title>Consensus on criteria for acromegaly diagnosis and remission</article-title>. <source>Pituitary</source>. (<year>2024</year>) <volume>27</volume>:<fpage>7</fpage>&#x2013;<lpage>22</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-023-01360-1</pub-id>, PMID: <pub-id pub-id-type="pmid">37923946</pub-id>
</mixed-citation>
</ref>
<ref id="B4">
<label>4</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Esposito</surname> <given-names>D</given-names></name>
<name><surname>Ragnarsson</surname> <given-names>O</given-names></name>
<name><surname>Johannsson</surname> <given-names>G</given-names></name>
<name><surname>Olsson</surname> <given-names>DS</given-names></name>
</person-group>. 
<article-title>Prolonged diagnostic delay in acromegaly is associated with increased morbidity and mortality</article-title>. <source>Eur J Endocrinol</source>. (<year>2020</year>) <volume>182</volume>:<page-range>523&#x2013;31</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-20-0019</pub-id>, PMID: <pub-id pub-id-type="pmid">32213651</pub-id>
</mixed-citation>
</ref>
<ref id="B5">
<label>5</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Giustina</surname> <given-names>A</given-names></name>
<name><surname>Barkhoudarian</surname> <given-names>G</given-names></name>
<name><surname>Beckers</surname> <given-names>A</given-names></name>
<name><surname>Ben-Shlomo</surname> <given-names>A</given-names></name>
<name><surname>Biermasz</surname> <given-names>N</given-names></name>
<name><surname>Biller</surname> <given-names>B</given-names></name>
<etal/>
</person-group>. 
<article-title>Multidisciplinary management of acromegaly: a consensus</article-title>. <source>Rev Endocr Metab Disord</source>. (<year>2020</year>) <volume>21</volume>:<page-range>667&#x2013;78</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11154-020-09588-z</pub-id>, PMID: <pub-id pub-id-type="pmid">32914330</pub-id>
</mixed-citation>
</ref>
<ref id="B6">
<label>6</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Starnoni</surname> <given-names>D</given-names></name>
<name><surname>Daniel</surname> <given-names>RT</given-names></name>
<name><surname>Marino</surname> <given-names>L</given-names></name>
<name><surname>Pitteloud</surname> <given-names>N</given-names></name>
<name><surname>Levivier</surname> <given-names>M</given-names></name>
<name><surname>Messerer</surname> <given-names>M</given-names></name>
</person-group>. 
<article-title>Surgical treatment of acromegaly according to the 2010 remission criteria: systematic review and meta-analysis</article-title>. <source>Acta Neurochir (Wien)</source>. (<year>2016</year>) <volume>158</volume>:<page-range>2109&#x2013;21</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s00701-016-2903-4</pub-id>, PMID: <pub-id pub-id-type="pmid">27586125</pub-id>
</mixed-citation>
</ref>
<ref id="B7">
<label>7</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Melmed</surname> <given-names>S</given-names></name>
<name><surname>Di Filippo</surname> <given-names>L</given-names></name>
<name><surname>Fleseriu</surname> <given-names>M</given-names></name>
<name><surname>Mercado</surname> <given-names>M</given-names></name>
<name><surname>Karavitaki</surname> <given-names>N</given-names></name>
<name><surname>Gurnell</surname> <given-names>M</given-names></name>
<etal/>
</person-group>. 
<article-title>Consensus on acromegaly therapeutic outcomes: an update</article-title>. <source>Nat Rev Endocrinol</source>. (<year>2025</year>). <volume>21</volume>:<page-range>718&#x2013;737</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41574-025-01148-2</pub-id>, PMID: <pub-id pub-id-type="pmid">40804505</pub-id>
</mixed-citation>
</ref>
<ref id="B8">
<label>8</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Bolfi</surname> <given-names>F</given-names></name>
<name><surname>Neves</surname> <given-names>AF</given-names></name>
<name><surname>Boguszewski</surname> <given-names>CL</given-names></name>
<name><surname>Nunes-Nogueira</surname> <given-names>VS</given-names></name>
</person-group>. 
<article-title>Mortality in acromegaly decreased in the last decade: a systematic review and meta-analysis</article-title>. <source>Eur J Endocrinol</source>. (<year>2018</year>) <volume>179</volume>:<fpage>59</fpage>&#x2013;<lpage>71</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-18-0255</pub-id>, PMID: <pub-id pub-id-type="pmid">29764907</pub-id>
</mixed-citation>
</ref>
<ref id="B9">
<label>9</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Biermasz</surname> <given-names>NR</given-names></name>
<name><surname>van Thiel</surname> <given-names>SW</given-names></name>
<name><surname>Pereira</surname> <given-names>AM</given-names></name>
<name><surname>Hoftijzer</surname> <given-names>HC</given-names></name>
<name><surname>van Hemert</surname> <given-names>AM</given-names></name>
<name><surname>Smit</surname> <given-names>JW</given-names></name>
<etal/>
</person-group>. 
<article-title>Decreased quality of life in patients with acromegaly despite long-term cure of growth hormone excess</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>2004</year>) <volume>89</volume>:<page-range>5369&#x2013;76</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jc.2004-0669</pub-id>, PMID: <pub-id pub-id-type="pmid">15531483</pub-id>
</mixed-citation>
</ref>
<ref id="B10">
<label>10</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Andela</surname> <given-names>CD</given-names></name>
<name><surname>Scharloo</surname> <given-names>M</given-names></name>
<name><surname>Pereira</surname> <given-names>AM</given-names></name>
<name><surname>Kaptein</surname> <given-names>AA</given-names></name>
<name><surname>Biermasz</surname> <given-names>NR</given-names></name>
</person-group>. 
<article-title>Quality of life (QoL) impairments in patients with a pituitary adenoma: a systematic review of QoL studies</article-title>. <source>Pituitary</source>. (<year>2015</year>) <volume>18</volume>:<page-range>752&#x2013;76</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-015-0636-7</pub-id>, PMID: <pub-id pub-id-type="pmid">25605584</pub-id>
</mixed-citation>
</ref>
<ref id="B11">
<label>11</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Geer</surname> <given-names>EB</given-names></name>
<name><surname>Sisco</surname> <given-names>J</given-names></name>
<name><surname>Adelman</surname> <given-names>DT</given-names></name>
<name><surname>Ludlam</surname> <given-names>WH</given-names></name>
<name><surname>Haviv</surname> <given-names>A</given-names></name>
<name><surname>Gelbaum</surname> <given-names>D</given-names></name>
<etal/>
</person-group>. 
<article-title>Observed discordance between outcomes reported by acromegaly patients and their treating endocrinology medical provider</article-title>. <source>Pituitary</source>. (<year>2020</year>) <volume>23</volume>:<page-range>140&#x2013;8</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-019-01013-2</pub-id>, PMID: <pub-id pub-id-type="pmid">31808101</pub-id>
</mixed-citation>
</ref>
<ref id="B12">
<label>12</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Shah</surname> <given-names>SN</given-names></name>
<name><surname>Yuen</surname> <given-names>KCJ</given-names></name>
<name><surname>Bonert</surname> <given-names>V</given-names></name>
<name><surname>Huang</surname> <given-names>W</given-names></name>
<name><surname>Sisco</surname> <given-names>J</given-names></name>
<name><surname>Palaty</surname> <given-names>C</given-names></name>
<etal/>
</person-group>. 
<article-title>Patient perspectives on acromegaly disease burden: insights from a community meeting</article-title>. <source>Front Endocrinol (Lausanne)</source>. (<year>2025</year>) <volume>16</volume>:<elocation-id>1516131</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3389/fendo.2025.1516131</pub-id>, PMID: <pub-id pub-id-type="pmid">39963277</pub-id>
</mixed-citation>
</ref>
<ref id="B13">
<label>13</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Melmed</surname> <given-names>S</given-names></name>
</person-group>. 
<article-title>Pathogenesis of pituitary tumors</article-title>. <source>Nat Rev Endocrinol</source>. (<year>2011</year>) <volume>7</volume>:<page-range>257&#x2013;66</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/nrendo.2011.40</pub-id>, PMID: <pub-id pub-id-type="pmid">21423242</pub-id>
</mixed-citation>
</ref>
<ref id="B14">
<label>14</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Melmed</surname> <given-names>S</given-names></name>
<name><surname>Kaiser</surname> <given-names>UB</given-names></name>
<name><surname>Lopes</surname> <given-names>MB</given-names></name>
<name><surname>Bertherat</surname> <given-names>J</given-names></name>
<name><surname>Syro</surname> <given-names>LV</given-names></name>
<name><surname>Raverot</surname> <given-names>G</given-names></name>
<etal/>
</person-group>. 
<article-title>Clinical biology of the pituitary adenoma</article-title>. <source>Endocr Rev</source>. (<year>2022</year>) <volume>43</volume>:<page-range>1003&#x2013;37</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/endrev/bnac010</pub-id>, PMID: <pub-id pub-id-type="pmid">35395078</pub-id>
</mixed-citation>
</ref>
<ref id="B15">
<label>15</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Landis</surname> <given-names>CA</given-names></name>
<name><surname>Masters</surname> <given-names>SB</given-names></name>
<name><surname>Spada</surname> <given-names>A</given-names></name>
<name><surname>Pace</surname> <given-names>AM</given-names></name>
<name><surname>Bourne</surname> <given-names>HR</given-names></name>
<name><surname>Vallar</surname> <given-names>L</given-names></name>
</person-group>. 
<article-title>GTPase inhibiting mutations activate the &#x3b1; chain of G<sub>s</sub> and stimulate adenylyl cyclase in human pituitary tumours</article-title>. <source>Nature</source>. (<year>1989</year>) <volume>340</volume>:<page-range>692&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/340692a0</pub-id>, PMID: <pub-id pub-id-type="pmid">2549426</pub-id>
</mixed-citation>
</ref>
<ref id="B16">
<label>16</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lyons</surname> <given-names>J</given-names></name>
<name><surname>Landis</surname> <given-names>CA</given-names></name>
<name><surname>Harsh</surname> <given-names>G</given-names></name>
<name><surname>Vallar</surname> <given-names>L</given-names></name>
<name><surname>Gr&#xfc;newald</surname> <given-names>K</given-names></name>
<name><surname>Feichtinger</surname> <given-names>H</given-names></name>
<etal/>
</person-group>. 
<article-title>Two G protein oncogenes in human endocrine tumors</article-title>. <source>Science</source>. (<year>1990</year>) <volume>249</volume>:<page-range>655&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1126/science.2116665</pub-id>, PMID: <pub-id pub-id-type="pmid">2116665</pub-id>
</mixed-citation>
</ref>
<ref id="B17">
<label>17</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Landis</surname> <given-names>CA</given-names></name>
<name><surname>Harsh</surname> <given-names>G</given-names></name>
<name><surname>Lyons</surname> <given-names>J</given-names></name>
<name><surname>Davis</surname> <given-names>RL</given-names></name>
<name><surname>McCormick</surname> <given-names>F</given-names></name>
<name><surname>Bourne</surname> <given-names>HR</given-names></name>
</person-group>. 
<article-title>Clinical characteristics of acromegalic patients whose pituitary tumors contain mutant G<sub>s</sub> protein</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1990</year>) <volume>71</volume>:<page-range>1416&#x2013;20</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem-71-6-1416</pub-id>, PMID: <pub-id pub-id-type="pmid">2121775</pub-id>
</mixed-citation>
</ref>
<ref id="B18">
<label>18</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Adams</surname> <given-names>EF</given-names></name>
<name><surname>Brockmeier</surname> <given-names>S</given-names></name>
<name><surname>Friedmann</surname> <given-names>E</given-names></name>
<name><surname>Roth</surname> <given-names>M</given-names></name>
<name><surname>Buchfelder</surname> <given-names>M</given-names></name>
<name><surname>Fahlbusch</surname> <given-names>R</given-names></name>
</person-group>. 
<article-title>Clinical and biochemical characteristics of acromegalic patients harboring <italic>gsp</italic>-positive and <italic>gsp</italic>-negative pituitary tumors</article-title>. <source>Neurosurgery</source>. (<year>1993</year>) <volume>33</volume>:<fpage>198</fpage>&#x2013;<lpage>203</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1227/00006123-199308000-00003</pub-id>, PMID: <pub-id pub-id-type="pmid">8396223</pub-id>
</mixed-citation>
</ref>
<ref id="B19">
<label>19</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Barlier</surname> <given-names>A</given-names></name>
<name><surname>Gunz</surname> <given-names>G</given-names></name>
<name><surname>Zamora</surname> <given-names>AJ</given-names></name>
<name><surname>Morange-Ramos</surname> <given-names>I</given-names></name>
<name><surname>Figarella-Branger</surname> <given-names>D</given-names></name>
<name><surname>Dufour</surname> <given-names>H</given-names></name>
<etal/>
</person-group>. 
<article-title>Pronostic and therapeutic consequences of G<sub>s</sub>&#x3b1; mutations in somatotroph adenomas</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1998</year>) <volume>83</volume>:<page-range>1604&#x2013;10</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.83.5.4797</pub-id>, PMID: <pub-id pub-id-type="pmid">9589663</pub-id>
</mixed-citation>
</ref>
<ref id="B20">
<label>20</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Kim</surname> <given-names>H</given-names></name>
<name><surname>Kim</surname> <given-names>M</given-names></name>
<name><surname>Park</surname> <given-names>Y</given-names></name>
<name><surname>Kim</surname> <given-names>S</given-names></name>
<name><surname>Park</surname> <given-names>D</given-names></name>
<name><surname>Park</surname> <given-names>K</given-names></name>
<etal/>
</person-group>. 
<article-title>Prevalence of Gs alpha mutations in Korean patients with pituitary adenomas</article-title>. <source>J Endocrinol</source>. (<year>2001</year>) <volume>168</volume>:<page-range>221&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1677/joe.0.1680221</pub-id>, PMID: <pub-id pub-id-type="pmid">11182759</pub-id>
</mixed-citation>
</ref>
<ref id="B21">
<label>21</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Yang</surname> <given-names>I</given-names></name>
<name><surname>Park</surname> <given-names>S</given-names></name>
<name><surname>Ryu</surname> <given-names>M</given-names></name>
<name><surname>Woo</surname> <given-names>J</given-names></name>
<name><surname>Kim</surname> <given-names>S</given-names></name>
<name><surname>Kim</surname> <given-names>J</given-names></name>
<etal/>
</person-group>. 
<article-title>Characteristics of <italic>gsp</italic>-positive growth hormone-secreting pituitary tumors in Korean acromegalic patients</article-title>. <source>Eur J Endocrinol</source>. (<year>1996</year>) <volume>134</volume>:<page-range>720&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje.0.1340720</pub-id>, PMID: <pub-id pub-id-type="pmid">8766942</pub-id>
</mixed-citation>
</ref>
<ref id="B22">
<label>22</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Mendoza</surname> <given-names>V</given-names></name>
<name><surname>Sosa</surname> <given-names>E</given-names></name>
<name><surname>Espinosa-de-Los-Monteros</surname> <given-names>AL</given-names></name>
<name><surname>Salcedo</surname> <given-names>M</given-names></name>
<name><surname>Guinto</surname> <given-names>G</given-names></name>
<name><surname>Cheng</surname> <given-names>S</given-names></name>
<etal/>
</person-group>. 
<article-title>GSP&#x3b1; mutations in Mexican patients with acromegaly: potential impact on long term prognosis</article-title>. <source>Growth Horm IGF Res</source>. (<year>2005</year>) <volume>15</volume>:<fpage>28</fpage>&#x2013;<lpage>32</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.ghir.2004.10.001</pub-id>, PMID: <pub-id pub-id-type="pmid">15701569</pub-id>
</mixed-citation>
</ref>
<ref id="B23">
<label>23</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Freda</surname> <given-names>PU</given-names></name>
<name><surname>Chung</surname> <given-names>WK</given-names></name>
<name><surname>Matsuoka</surname> <given-names>N</given-names></name>
<name><surname>Walsh</surname> <given-names>JE</given-names></name>
<name><surname>Kanibir</surname> <given-names>MN</given-names></name>
<name><surname>Kleinman</surname> <given-names>G</given-names></name>
<etal/>
</person-group>. 
<article-title>Analysis of <italic>GNAS</italic> mutations in 60 growth hormone secreting pituitary tumors: correlation with clinical and pathological characteristics and surgical outcome based on highly sensitive GH and IGF-I criteria for remission</article-title>. <source>Pituitary</source>. (<year>2007</year>) <volume>10</volume>:<page-range>275&#x2013;82</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-007-0058-2</pub-id>, PMID: <pub-id pub-id-type="pmid">17594522</pub-id>
</mixed-citation>
</ref>
<ref id="B24">
<label>24</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Jaffrain-Rea</surname> <given-names>M-L</given-names></name>
<name><surname>Rotondi</surname> <given-names>S</given-names></name>
<name><surname>Turchi</surname> <given-names>A</given-names></name>
<name><surname>Occhi</surname> <given-names>G</given-names></name>
<name><surname>Barlier</surname> <given-names>A</given-names></name>
<name><surname>Peverelli</surname> <given-names>E</given-names></name>
<etal/>
</person-group>. 
<article-title>Somatostatin analogues increase AIP expression in somatotropinomas, irrespective of <italic>Gsp</italic> mutations</article-title>. <source>Endocr Relat Cancer</source>. (<year>2013</year>) <volume>20</volume>:<page-range>753&#x2013;66</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/erc-12-0322</pub-id>, PMID: <pub-id pub-id-type="pmid">23940012</pub-id>
</mixed-citation>
</ref>
<ref id="B25">
<label>25</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Larkin</surname> <given-names>S</given-names></name>
<name><surname>Reddy</surname> <given-names>R</given-names></name>
<name><surname>Karavitaki</surname> <given-names>N</given-names></name>
<name><surname>Cudlip</surname> <given-names>S</given-names></name>
<name><surname>Wass</surname> <given-names>J</given-names></name>
<name><surname>Ansorge</surname> <given-names>O</given-names></name>
</person-group>. 
<article-title>Granulation pattern, but not <italic>GSP</italic> or <italic>GHR</italic> mutation, is associated with clinical characteristics in somatostatin-na&#xef;ve patients with somatotroph adenomas</article-title>. <source>Eur J Endocrinol</source>. (<year>2013</year>) <volume>168</volume>:<page-range>491&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-12-0864</pub-id>, PMID: <pub-id pub-id-type="pmid">23288882</pub-id>
</mixed-citation>
</ref>
<ref id="B26">
<label>26</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Mayr</surname> <given-names>B</given-names></name>
<name><surname>Buslei</surname> <given-names>R</given-names></name>
<name><surname>Theodoropoulou</surname> <given-names>M</given-names></name>
<name><surname>Stalla</surname> <given-names>GK</given-names></name>
<name><surname>Buchfelder</surname> <given-names>M</given-names></name>
<name><surname>Sch&#xf6;fl</surname> <given-names>C</given-names></name>
</person-group>. 
<article-title>Molecular and functional properties of densely and sparsely granulated GH-producing pituitary adenomas</article-title>. <source>Eur J Endocrinol</source>. (<year>2013</year>) <volume>169</volume>:<fpage>391</fpage>&#x2013;<lpage>400</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-13-0134</pub-id>, PMID: <pub-id pub-id-type="pmid">23847328</pub-id>
</mixed-citation>
</ref>
<ref id="B27">
<label>27</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Matsumoto</surname> <given-names>R</given-names></name>
<name><surname>Izawa</surname> <given-names>M</given-names></name>
<name><surname>Fukuoka</surname> <given-names>H</given-names></name>
<name><surname>Iguchi</surname> <given-names>G</given-names></name>
<name><surname>Odake</surname> <given-names>Y</given-names></name>
<name><surname>Yoshida</surname> <given-names>K</given-names></name>
<etal/>
</person-group>. 
<article-title>Genetic and clinical characteristics of Japanese patients with sporadic somatotropinoma</article-title>. <source>Endocr J</source>. (<year>2016</year>) <volume>63</volume>:<page-range>953&#x2013;63</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1507/endocrj.ej16-0075</pub-id>, PMID: <pub-id pub-id-type="pmid">27498687</pub-id>
</mixed-citation>
</ref>
<ref id="B28">
<label>28</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Ritvonen</surname> <given-names>E</given-names></name>
<name><surname>Pitk&#xe4;nen</surname> <given-names>E</given-names></name>
<name><surname>Karppinen</surname> <given-names>A</given-names></name>
<name><surname>Vehkavaara</surname> <given-names>S</given-names></name>
<name><surname>Demir</surname> <given-names>H</given-names></name>
<name><surname>Paetau</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Impact of AIP and inhibitory G protein alpha 2 proteins on clinical features of sporadic GH-secreting pituitary adenomas</article-title>. <source>Eur J Endocrinol</source>. (<year>2017</year>) <volume>176</volume>:<page-range>243&#x2013;52</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-16-0620</pub-id>, PMID: <pub-id pub-id-type="pmid">27998919</pub-id>
</mixed-citation>
</ref>
<ref id="B29">
<label>29</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Tang</surname> <given-names>C</given-names></name>
<name><surname>Zhong</surname> <given-names>C</given-names></name>
<name><surname>Cong</surname> <given-names>Z</given-names></name>
<name><surname>Yang</surname> <given-names>J</given-names></name>
<name><surname>Wen</surname> <given-names>G</given-names></name>
<name><surname>Zhu</surname> <given-names>J</given-names></name>
<etal/>
</person-group>. 
<article-title>MEG3 is associated with gsp oncogene regulation of growth hormone hypersecretion, proliferation and invasiveness of human GH&#x2212;secreting adenomas</article-title>. <source>Oncol Lett</source>. (<year>2019</year>). <volume>17</volume>:<page-range>3495&#x2013;3502</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.3892/ol.2019.10006</pub-id>, PMID: <pub-id pub-id-type="pmid">30867789</pub-id>
</mixed-citation>
</ref>
<ref id="B30">
<label>30</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Jung</surname> <given-names>H</given-names></name>
<name><surname>Kim</surname> <given-names>K</given-names></name>
<name><surname>Kim</surname> <given-names>D</given-names></name>
<name><surname>Moon</surname> <given-names>JH</given-names></name>
<name><surname>Kim</surname> <given-names>EH</given-names></name>
<name><surname>Kim</surname> <given-names>SH</given-names></name>
<etal/>
</person-group>. 
<article-title>Associations of <italic>GNAS</italic> mutations with surgical outcomes in patients with growth hormone-secreting pituitary adenoma</article-title>. <source>Endocrinol Metab (Seoul)</source>. (<year>2021</year>) <volume>36</volume>:<page-range>342&#x2013;50</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.3803/enm.2020.875</pub-id>, PMID: <pub-id pub-id-type="pmid">33752302</pub-id>
</mixed-citation>
</ref>
<ref id="B31">
<label>31</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Wildemberg</surname> <given-names>LE</given-names></name>
<name><surname>Henriques</surname> <given-names>D</given-names></name>
<name><surname>Elias</surname> <given-names>PCL</given-names></name>
<name><surname>Lima</surname> <given-names>CHDA</given-names></name>
<name><surname>Musolino</surname> <given-names>NRDC</given-names></name>
<name><surname>Camacho</surname> <given-names>AHS</given-names></name>
<etal/>
</person-group>. 
<article-title><italic>Gsp</italic> mutation is not a molecular biomarker of long-term response to first-generation somatostatin receptor ligands in acromegaly</article-title>. <source>Cancers (Basel)</source>. (<year>2021</year>) <volume>13</volume>:<elocation-id>4857</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/cancers13194857</pub-id>, PMID: <pub-id pub-id-type="pmid">34638340</pub-id>
</mixed-citation>
</ref>
<ref id="B32">
<label>32</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Yamato</surname> <given-names>A</given-names></name>
<name><surname>Nagano</surname> <given-names>H</given-names></name>
<name><surname>Gao</surname> <given-names>Y</given-names></name>
<name><surname>Matsuda</surname> <given-names>T</given-names></name>
<name><surname>Hashimoto</surname> <given-names>N</given-names></name>
<name><surname>Nakayama</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Proteogenomic landscape and clinical characterization of GH-producing pituitary adenomas/somatotroph pituitary neuroendocrine tumors</article-title>. <source>Commun Biol</source>. (<year>2022</year>) <volume>5</volume>:<fpage>1304</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s42003-022-04272-1</pub-id>, PMID: <pub-id pub-id-type="pmid">36435867</pub-id>
</mixed-citation>
</ref>
<ref id="B33">
<label>33</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Yang</surname> <given-names>Y</given-names></name>
<name><surname>Yao</surname> <given-names>Y</given-names></name>
<name><surname>Deng</surname> <given-names>K</given-names></name>
<name><surname>Xing</surname> <given-names>B</given-names></name>
<name><surname>Lian</surname> <given-names>W</given-names></name>
<name><surname>You</surname> <given-names>H</given-names></name>
<etal/>
</person-group>. 
<article-title>Somatic <italic>GNAS</italic> mutations in acromegaly: prevalence, clinical features and gender differences</article-title>. <source>Endocr Connect</source>. (<year>2024</year>) <volume>14</volume>:<elocation-id>e240266</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/ec-24-0266</pub-id>, PMID: <pub-id pub-id-type="pmid">39513543</pub-id>
</mixed-citation>
</ref>
<ref id="B34">
<label>34</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Hozo</surname> <given-names>SP</given-names></name>
<name><surname>Djulbegovic</surname> <given-names>B</given-names></name>
<name><surname>Hozo</surname> <given-names>I</given-names></name>
</person-group>. 
<article-title>Estimating the mean and variance from the median, range, and the size of a sample</article-title>. <source>BMC Med Res Methodol</source>. (<year>2005</year>) <volume>5</volume>:<fpage>13</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1186/1471-2288-5-13</pub-id>, PMID: <pub-id pub-id-type="pmid">15840177</pub-id>
</mixed-citation>
</ref>
<ref id="B35">
<label>35</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Wan</surname> <given-names>X</given-names></name>
<name><surname>Wang</surname> <given-names>W</given-names></name>
<name><surname>Liu</surname> <given-names>J</given-names></name>
<name><surname>Tong</surname> <given-names>T</given-names></name>
</person-group>. 
<article-title>Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range</article-title>. <source>BMC Med Res Methodol</source>. (<year>2014</year>) <volume>14</volume>:<elocation-id>135</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1186/1471-2288-14-135</pub-id>, PMID: <pub-id pub-id-type="pmid">25524443</pub-id>
</mixed-citation>
</ref>
<ref id="B36">
<label>36</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Luo</surname> <given-names>D</given-names></name>
<name><surname>Wan</surname> <given-names>X</given-names></name>
<name><surname>Liu</surname> <given-names>J</given-names></name>
<name><surname>Tong</surname> <given-names>T</given-names></name>
</person-group>. 
<article-title>Optimally estimating the sample mean from the sample size, median, mid-range, and/or mid-quartile range</article-title>. <source>Stat Methods Med Res</source>. (<year>2018</year>) <volume>27</volume>:<page-range>1785&#x2013;805</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1177/0962280216669183</pub-id>, PMID: <pub-id pub-id-type="pmid">27683581</pub-id>
</mixed-citation>
</ref>
<ref id="B37">
<label>37</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Thakker</surname> <given-names>RV</given-names></name>
<name><surname>Pook</surname> <given-names>MA</given-names></name>
<name><surname>Wooding</surname> <given-names>C</given-names></name>
<name><surname>Boscaro</surname> <given-names>M</given-names></name>
<name><surname>Scanarini</surname> <given-names>M</given-names></name>
<name><surname>Clayton</surname> <given-names>RN</given-names></name>
</person-group>. 
<article-title>Association of somatotrophinomas with loss of alleles on chromosome 11 and with <italic>gsp</italic> mutations</article-title>. <source>J Clin Invest</source>. (<year>1993</year>) <volume>91</volume>:<page-range>2815&#x2013;21</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1172/jci116524</pub-id>, PMID: <pub-id pub-id-type="pmid">8514889</pub-id>
</mixed-citation>
</ref>
<ref id="B38">
<label>38</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Foltran</surname> <given-names>RK</given-names></name>
<name><surname>Amorim</surname> <given-names>PVGH</given-names></name>
<name><surname>Duarte</surname> <given-names>FH</given-names></name>
<name><surname>Grande</surname> <given-names>IPP</given-names></name>
<name><surname>Freire</surname> <given-names>ACTB</given-names></name>
<name><surname>Frassetto</surname> <given-names>FP</given-names></name>
<etal/>
</person-group>. 
<article-title>Study of major genetic factors involved in pituitary tumorigenesis and their impact on clinical and biological characteristics of sporadic somatotropinomas and non-functioning pituitary adenomas</article-title>. <source>Braz J Med Biol Res</source>. (<year>2018</year>) <volume>51</volume>:<elocation-id>e7427</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1590/1414-431x20187427</pub-id>, PMID: <pub-id pub-id-type="pmid">29947650</pub-id>
</mixed-citation>
</ref>
<ref id="B39">
<label>39</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Ronchi</surname> <given-names>CL</given-names></name>
<name><surname>Peverelli</surname> <given-names>E</given-names></name>
<name><surname>Herterich</surname> <given-names>S</given-names></name>
<name><surname>Weigand</surname> <given-names>I</given-names></name>
<name><surname>Mantovani</surname> <given-names>G</given-names></name>
<name><surname>Schwarzmayr</surname> <given-names>T</given-names></name>
<etal/>
</person-group>. 
<article-title>Landscape of somatic mutations in sporadic GH-secreting pituitary adenomas</article-title>. <source>Eur J Endocrinol</source>. (<year>2016</year>) <volume>174</volume>:<page-range>363&#x2013;72</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-15-1064</pub-id>, PMID: <pub-id pub-id-type="pmid">26701869</pub-id>
</mixed-citation>
</ref>
<ref id="B40">
<label>40</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Shi</surname> <given-names>Y</given-names></name>
<name><surname>Tang</surname> <given-names>D</given-names></name>
<name><surname>Deng</surname> <given-names>J</given-names></name>
<name><surname>Su</surname> <given-names>C</given-names></name>
</person-group>. 
<article-title>Detection of gsp oncogene in growth hormone-secreting pituitary adenomas and the study of clinical characteristics of acromegalic patients with gsp-positive pituitary tumors</article-title>. <source>Chin Med J (Engl)</source>. (<year>1998</year>) <volume>111</volume>:<page-range>891&#x2013;4</page-range>., PMID: <pub-id pub-id-type="pmid">11189233</pub-id>
</mixed-citation>
</ref>
<ref id="B41">
<label>41</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Goto</surname> <given-names>Y</given-names></name>
<name><surname>Kinoshita</surname> <given-names>M</given-names></name>
<name><surname>Oshino</surname> <given-names>S</given-names></name>
<name><surname>Arita</surname> <given-names>H</given-names></name>
<name><surname>Kitamura</surname> <given-names>T</given-names></name>
<name><surname>Otsuki</surname> <given-names>M</given-names></name>
<etal/>
</person-group>. 
<article-title><italic>Gsp</italic> mutation in acromegaly and its influence on TRH-induced paradoxical GH response</article-title>. <source>Clin Endocrinol (Oxf)</source>. (<year>2014</year>) <volume>80</volume>:<page-range>714&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/cen.12336</pub-id>, PMID: <pub-id pub-id-type="pmid">24111551</pub-id>
</mixed-citation>
</ref>
<ref id="B42">
<label>42</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Puig-Domingo</surname> <given-names>M</given-names></name>
<name><surname>Gil</surname> <given-names>J</given-names></name>
<name><surname>Sampedro-Nu&#xf1;ez</surname> <given-names>M</given-names></name>
<name><surname>Jord&#xe0;</surname> <given-names>M</given-names></name>
<name><surname>Webb</surname> <given-names>SM</given-names></name>
<name><surname>Serra</surname> <given-names>G</given-names></name>
<etal/>
</person-group>. 
<article-title>Molecular profiling for acromegaly treatment: a validation study</article-title>. <source>Endocr Relat Cancer</source>. (<year>2020</year>) <volume>27</volume>:<page-range>375&#x2013;89</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/erc-18-0565</pub-id>, PMID: <pub-id pub-id-type="pmid">32302973</pub-id>
</mixed-citation>
</ref>
<ref id="B43">
<label>43</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Bakhtiar</surname> <given-names>Y</given-names></name>
<name><surname>Hirano</surname> <given-names>H</given-names></name>
<name><surname>Arita</surname> <given-names>K</given-names></name>
<name><surname>Yunoue</surname> <given-names>S</given-names></name>
<name><surname>Fujio</surname> <given-names>S</given-names></name>
<name><surname>Tominaga</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Relationship between cytokeratin staining patterns and clinico-pathological features in somatotropinomae</article-title>. <source>Eur J Endocrinol</source>. (<year>2010</year>) <volume>163</volume>:<page-range>531&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje-10-0586</pub-id>, PMID: <pub-id pub-id-type="pmid">20688896</pub-id>
</mixed-citation>
</ref>
<ref id="B44">
<label>44</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Fougner</surname> <given-names>SL</given-names></name>
<name><surname>Casar-Borota</surname> <given-names>O</given-names></name>
<name><surname>Heck</surname> <given-names>A</given-names></name>
<name><surname>Berg</surname> <given-names>JP</given-names></name>
<name><surname>Bollerslev</surname> <given-names>J</given-names></name>
</person-group>. 
<article-title>Adenoma granulation pattern correlates with clinical variables and effect of somatostatin analogue treatment in a large series of patients with acromegaly</article-title>. <source>Clin Endocrinol (Oxf)</source>. (<year>2012</year>) <volume>76</volume>:<fpage>96</fpage>&#x2013;<lpage>102</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/j.1365-2265.2011.04163.x</pub-id>, PMID: <pub-id pub-id-type="pmid">21722151</pub-id>
</mixed-citation>
</ref>
<ref id="B45">
<label>45</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Taboada</surname> <given-names>GF</given-names></name>
<name><surname>Tabet</surname> <given-names>ALO</given-names></name>
<name><surname>Naves</surname> <given-names>LA</given-names></name>
<name><surname>De Carvalho</surname> <given-names>DP</given-names></name>
<name><surname>Gadelha</surname> <given-names>MR</given-names></name>
</person-group>. 
<article-title>Prevalence of <italic>gsp</italic> oncogene in somatotropinomas and clinically non-functioning pituitary adenomas: our experience</article-title>. <source>Pituitary</source>. (<year>2009</year>) <volume>12</volume>:<page-range>165&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-008-0136-0</pub-id>, PMID: <pub-id pub-id-type="pmid">18642089</pub-id>
</mixed-citation>
</ref>
<ref id="B46">
<label>46</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Taboada</surname> <given-names>GF</given-names></name>
<name><surname>Neto</surname> <given-names>LV</given-names></name>
<name><surname>Luque</surname> <given-names>RM</given-names></name>
<name><surname>C&#xf3;rdoba-Chac&#xf3;n</surname> <given-names>J</given-names></name>
<name><surname>de Oliveira MaChado</surname> <given-names>E</given-names></name>
<name><surname>de Carvalho</surname> <given-names>DP</given-names></name>
<etal/>
</person-group>. 
<article-title>Impact of <italic>gsp</italic> oncogene on the mRNA content for somatostatin and dopamine receptors in human somatotropinomas</article-title>. <source>Neuroendocrinology</source>. (<year>2011</year>) <volume>93</volume>:<page-range>40&#x2013;7</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1159/000322040</pub-id>, PMID: <pub-id pub-id-type="pmid">21079388</pub-id>
</mixed-citation>
</ref>
<ref id="B47">
<label>47</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Hosoi</surname> <given-names>E</given-names></name>
<name><surname>Yokogoshi</surname> <given-names>Y</given-names></name>
<name><surname>Hosoi</surname> <given-names>E</given-names></name>
<name><surname>Horie</surname> <given-names>H</given-names></name>
<name><surname>Sano</surname> <given-names>T</given-names></name>
<name><surname>Yamada</surname> <given-names>S</given-names></name>
<etal/>
</person-group>. 
<article-title>Analysis of the Gs &#x3b1; gene in growth hormone-secreting pituitary adenomas by the polymerase chain reaction-direct sequencing method using paraffin-embedded tissues</article-title>. <source>Acta Endocrinol (Copenh)</source>. (<year>1993</year>) <volume>129</volume>:<page-range>301&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/acta.0.1290301</pub-id>, PMID: <pub-id pub-id-type="pmid">8237246</pub-id>
</mixed-citation>
</ref>
<ref id="B48">
<label>48</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Yoshimoto</surname> <given-names>K</given-names></name>
<name><surname>Iwahana</surname> <given-names>H</given-names></name>
<name><surname>Fukuda</surname> <given-names>A</given-names></name>
<name><surname>Sano</surname> <given-names>T</given-names></name>
<name><surname>Itakura</surname> <given-names>M</given-names></name>
</person-group>. 
<article-title>Rare mutations of the Gs alpha subunit gene in human endocrine tumors. Mutation detection by polymerase chain reaction&#x2014;primer-introduced restriction analysis</article-title>. <source>Cancer</source>. (<year>1993</year>) <volume>72</volume>:<page-range>1386&#x2013;93</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1002/1097-0142(19930815)72:4&lt;1386::aid-cncr2820720439&gt;3.0.co;2-j</pub-id>, PMID: <pub-id pub-id-type="pmid">8339229</pub-id>
</mixed-citation>
</ref>
<ref id="B49">
<label>49</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Faria</surname> <given-names>O</given-names></name>
<name><surname>Miranda</surname> <given-names>RL</given-names></name>
<name><surname>De Azeredo Lima</surname> <given-names>CH</given-names></name>
<name><surname>Guterres</surname> <given-names>A</given-names></name>
<name><surname>Ventura</surname> <given-names>N</given-names></name>
<name><surname>Barbosa</surname> <given-names>MA</given-names></name>
<etal/>
</person-group>. 
<article-title>Characterization of sporadic somatotropinomas with high GIP receptor expression</article-title>. <source>Pituitary</source>. (<year>2022</year>) <volume>25</volume>:<page-range>903&#x2013;10</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-022-01272-6</pub-id>, PMID: <pub-id pub-id-type="pmid">36066838</pub-id>
</mixed-citation>
</ref>
<ref id="B50">
<label>50</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>V&#xe4;lim&#xe4;ki</surname> <given-names>N</given-names></name>
<name><surname>Demir</surname> <given-names>H</given-names></name>
<name><surname>Pitk&#xe4;nen</surname> <given-names>E</given-names></name>
<name><surname>Kaasinen</surname> <given-names>E</given-names></name>
<name><surname>Karppinen</surname> <given-names>A</given-names></name>
<name><surname>Kivipelto</surname> <given-names>L</given-names></name>
<etal/>
</person-group>. 
<article-title>Whole-genome sequencing of growth hormone (GH)-secreting pituitary adenomas</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>2015</year>) <volume>100</volume>:<page-range>3918&#x2013;27</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jc.2015-3129</pub-id>, PMID: <pub-id pub-id-type="pmid">26280510</pub-id>
</mixed-citation>
</ref>
<ref id="B51">
<label>51</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Song</surname> <given-names>Z-J</given-names></name>
<name><surname>Reitman</surname> <given-names>ZJ</given-names></name>
<name><surname>Ma</surname> <given-names>Z-Y</given-names></name>
<name><surname>Chen</surname> <given-names>J-H</given-names></name>
<name><surname>Zhang</surname> <given-names>Q-L</given-names></name>
<name><surname>Shou</surname> <given-names>X-F</given-names></name>
<etal/>
</person-group>. 
<article-title>The genome-wide mutational landscape of pituitary adenomas</article-title>. <source>Cell Res</source>. (<year>2016</year>) <volume>26</volume>:<page-range>1255&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/cr.2016.114</pub-id>, PMID: <pub-id pub-id-type="pmid">27670697</pub-id>
</mixed-citation>
</ref>
<ref id="B52">
<label>52</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>V&#xe4;lim&#xe4;ki</surname> <given-names>N</given-names></name>
<name><surname>Schalin-J&#xe4;ntti</surname> <given-names>C</given-names></name>
<name><surname>Karppinen</surname> <given-names>A</given-names></name>
<name><surname>Paetau</surname> <given-names>A</given-names></name>
<name><surname>Kivipelto</surname> <given-names>L</given-names></name>
<name><surname>Aaltonen</surname> <given-names>LA</given-names></name>
<etal/>
</person-group>. 
<article-title>Genetic and epigenetic characterization of growth hormone&#x2013;secreting pituitary tumors</article-title>. <source>Mol Cancer Res</source>. (<year>2019</year>) <volume>17</volume>:<page-range>2432&#x2013;43</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1158/1541-7786.mcr-19-0434</pub-id>, PMID: <pub-id pub-id-type="pmid">31578227</pub-id>
</mixed-citation>
</ref>
<ref id="B53">
<label>53</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Ben-Shlomo</surname> <given-names>A</given-names></name>
<name><surname>Deng</surname> <given-names>N</given-names></name>
<name><surname>Ding</surname> <given-names>E</given-names></name>
<name><surname>Yamamoto</surname> <given-names>M</given-names></name>
<name><surname>Mamelak</surname> <given-names>A</given-names></name>
<name><surname>Chesnokova</surname> <given-names>V</given-names></name>
<etal/>
</person-group>. 
<article-title>DNA damage and growth hormone hypersecretion in pituitary somatotroph adenomas</article-title>. <source>J Clin Invest</source>. (<year>2020</year>) <volume>130</volume>:<page-range>5738&#x2013;55</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1172/jci138540</pub-id>, PMID: <pub-id pub-id-type="pmid">32673291</pub-id>
</mixed-citation>
</ref>
<ref id="B54">
<label>54</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Chiloiro</surname> <given-names>S</given-names></name>
<name><surname>Costanza</surname> <given-names>F</given-names></name>
<name><surname>Scaglione</surname> <given-names>GL</given-names></name>
<name><surname>Russo</surname> <given-names>F</given-names></name>
<name><surname>Nardelli</surname> <given-names>C</given-names></name>
<name><surname>Giampietro</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Genes of the &#x201c;regulation of lymphocyte activation&#x201d; pathway may influence immune cells infiltration in growth hormone secreting pituitary tumors</article-title>. <source>Pituitary</source>. (<year>2025</year>) <volume>28</volume>:<fpage>63</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-025-01537-w</pub-id>, PMID: <pub-id pub-id-type="pmid">40415137</pub-id>
</mixed-citation>
</ref>
<ref id="B55">
<label>55</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Bai</surname> <given-names>X</given-names></name>
<name><surname>Lei</surname> <given-names>T</given-names></name>
<name><surname>Liu</surname> <given-names>K</given-names></name>
</person-group>. 
<article-title>Clinical and biochemical characteristics of growth hormone-secreting pituitary tumors</article-title>. <source>J Tongji Med Univ</source>. (<year>2000</year>) <volume>20</volume>:<page-range>212&#x2013;3</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/bf02886993</pub-id>, PMID: <pub-id pub-id-type="pmid">11215051</pub-id>
</mixed-citation>
</ref>
<ref id="B56">
<label>56</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Harris</surname> <given-names>PE</given-names></name>
<name><surname>Alexander</surname> <given-names>JM</given-names></name>
<name><surname>Bikkal</surname> <given-names>HA</given-names></name>
<name><surname>Hsu</surname> <given-names>DW</given-names></name>
<name><surname>Hedley-Whyte</surname> <given-names>ET</given-names></name>
<name><surname>Klibanski</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Glycoprotein hormone &#x3b1;-subunit production in somatotroph adenomas with and without Gs&#x3b1; mutations</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1992</year>) <volume>75</volume>:<page-range>918&#x2013;23</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.75.3.1517386</pub-id>, PMID: <pub-id pub-id-type="pmid">1517386</pub-id>
</mixed-citation>
</ref>
<ref id="B57">
<label>57</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Adams</surname> <given-names>EF</given-names></name>
<name><surname>Lei</surname> <given-names>T</given-names></name>
<name><surname>Buchfelder</surname> <given-names>M</given-names></name>
<name><surname>Petersen</surname> <given-names>B</given-names></name>
<name><surname>Fahlbusch</surname> <given-names>R</given-names></name>
</person-group>. 
<article-title>Biochemical characteristics of human pituitary somatotropinomas with and without <italic>gsp</italic> mutations: <italic>in vitro</italic> cell culture studies</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1995</year>) <volume>80</volume>:<page-range>2077&#x2013;81</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.80.7.7608258</pub-id>, PMID: <pub-id pub-id-type="pmid">7608258</pub-id>
</mixed-citation>
</ref>
<ref id="B58">
<label>58</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lania</surname> <given-names>A</given-names></name>
<name><surname>Persani</surname> <given-names>L</given-names></name>
<name><surname>Ballar&#xe9;</surname> <given-names>E</given-names></name>
<name><surname>Mantovani</surname> <given-names>S</given-names></name>
<name><surname>Losa</surname> <given-names>M</given-names></name>
<name><surname>Spada</surname> <given-names>A</given-names></name>
</person-group>. 
<article-title>Constitutively active Gs&#x3b1; is associated with an increased phosphodiesterase activity in human growth hormone-secreting adenomas</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1998</year>) <volume>83</volume>:<page-range>1624&#x2013;8</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.83.5.4814</pub-id>, PMID: <pub-id pub-id-type="pmid">9589667</pub-id>
</mixed-citation>
</ref>
<ref id="B59">
<label>59</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Peri</surname> <given-names>A</given-names></name>
<name><surname>Conforti</surname> <given-names>B</given-names></name>
<name><surname>Baglioni-Peri</surname> <given-names>S</given-names></name>
<name><surname>Luciani</surname> <given-names>P</given-names></name>
<name><surname>Cioppi</surname> <given-names>F</given-names></name>
<name><surname>Buci</surname> <given-names>L</given-names></name>
<etal/>
</person-group>. 
<article-title>Expression of cyclic adenosine 3&#x2019;, 5&#x2019;-monophosphate (cAMP)-responsive element binding protein and inducible-cAMP early repressor genes in growth hormone-secreting pituitary adenomas with or without mutations of the <italic>Gs&#x3b1;</italic> gene</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>2001</year>) <volume>86</volume>:<page-range>2111&#x2013;7</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.86.5.7475</pub-id>, PMID: <pub-id pub-id-type="pmid">11344215</pub-id>
</mixed-citation>
</ref>
<ref id="B60">
<label>60</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Kim</surname> <given-names>K</given-names></name>
<name><surname>Sanno</surname> <given-names>N</given-names></name>
<name><surname>Arai</surname> <given-names>K</given-names></name>
<name><surname>Takano</surname> <given-names>K</given-names></name>
<name><surname>Yasufuku-Takano</surname> <given-names>J</given-names></name>
<name><surname>Teramoto</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Ghrelin mRNA and GH secretagogue receptor mRNA in human GH-producing pituitary adenomas is affected by mutations in the &#x3b1; subunit of G protein</article-title>. <source>Clin Endocrinol (Oxf)</source>. (<year>2003</year>) <volume>59</volume>:<page-range>630&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1046/j.1365-2265.2003.01898.x</pub-id>, PMID: <pub-id pub-id-type="pmid">14616888</pub-id>
</mixed-citation>
</ref>
<ref id="B61">
<label>61</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Yasufuku-Takano</surname> <given-names>J</given-names></name>
<name><surname>Takano</surname> <given-names>K</given-names></name>
<name><surname>Morita</surname> <given-names>K</given-names></name>
<name><surname>Takakura</surname> <given-names>K</given-names></name>
<name><surname>Teramoto</surname> <given-names>A</given-names></name>
<name><surname>Fujita</surname> <given-names>T</given-names></name>
</person-group>. 
<article-title>Does the prevalence of <italic>gsp</italic> mutations in GH-secreting pituitary adenomas differ geographically or racially? Prevalence of <italic>gsp</italic> mutations in Japanese patients revisited</article-title>. <source>Clin Endocrinol (Oxf)</source>. (<year>2006</year>) <volume>64</volume>:<page-range>91&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/j.1365-2265.2005.02423.x</pub-id>, PMID: <pub-id pub-id-type="pmid">16402935</pub-id>
</mixed-citation>
</ref>
<ref id="B62">
<label>62</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Sakai</surname> <given-names>N</given-names></name>
<name><surname>Kim</surname> <given-names>K</given-names></name>
<name><surname>Sanno</surname> <given-names>N</given-names></name>
<name><surname>Yoshida</surname> <given-names>D</given-names></name>
<name><surname>Teramoto</surname> <given-names>A</given-names></name>
<name><surname>Shibasaki</surname> <given-names>T</given-names></name>
</person-group>. 
<article-title>Elevation of growth hormone-releasing hormone receptor messenger ribonucleic acid expression in growth hormone-secreting pituitary adenoma with Gs&#x3b1; protein mutation</article-title>. <source>Neurol Med Chir (Tokyo)</source>. (<year>2008</year>) <volume>48</volume>:<page-range>481&#x2013;8</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.2176/nmc.48.481</pub-id>, PMID: <pub-id pub-id-type="pmid">19029774</pub-id>
</mixed-citation>
</ref>
<ref id="B63">
<label>63</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Nakashima</surname> <given-names>M</given-names></name>
<name><surname>Takano</surname> <given-names>K</given-names></name>
<name><surname>Matsuno</surname> <given-names>A</given-names></name>
</person-group>. 
<article-title>Analyses of factors influencing the acute effect of octreotide in growth hormone-secreting adenomas</article-title>. <source>Endocr J</source>. (<year>2009</year>) <volume>56</volume>:<fpage>295</fpage>&#x2013;<lpage>304</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1507/endocrj.k08e-305</pub-id>, PMID: <pub-id pub-id-type="pmid">19164866</pub-id>
</mixed-citation>
</ref>
<ref id="B64">
<label>64</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Xu</surname> <given-names>T</given-names></name>
<name><surname>Ye</surname> <given-names>F</given-names></name>
<name><surname>Wang</surname> <given-names>B</given-names></name>
<name><surname>Tian</surname> <given-names>C</given-names></name>
<name><surname>Wang</surname> <given-names>S</given-names></name>
<name><surname>Shu</surname> <given-names>K</given-names></name>
<etal/>
</person-group>. 
<article-title>Elevation of growth hormone secretagogue receptor type 1a mRNA expression in human growth hormone-secreting pituitary adenoma harboring G protein alpha subunit mutation</article-title>. <source>Neuro Endocrinol Lett</source>. (<year>2010</year>) <volume>31</volume>:<page-range>147&#x2013;54</page-range>., PMID: <pub-id pub-id-type="pmid">20150876</pub-id>
</mixed-citation>
</ref>
<ref id="B65">
<label>65</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Bertherat</surname> <given-names>J</given-names></name>
<name><surname>Chanson</surname> <given-names>P</given-names></name>
<name><surname>Montminy</surname> <given-names>M</given-names></name>
</person-group>. 
<article-title>The cyclic adenosine 3&#x2019;, 5&#x2019;-monophosphate-responsive factor CREB is constitutively activated in human somatotroph adenomas</article-title>. <source>Mol Endocrinol</source>. (<year>1995</year>) <volume>9</volume>:<page-range>777&#x2013;83</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/mend.9.7.7476961</pub-id>, PMID: <pub-id pub-id-type="pmid">7476961</pub-id>
</mixed-citation>
</ref>
<ref id="B66">
<label>66</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lania</surname> <given-names>A</given-names></name>
<name><surname>Filopanti</surname> <given-names>M</given-names></name>
<name><surname>Corbetta</surname> <given-names>S</given-names></name>
<name><surname>Losa</surname> <given-names>M</given-names></name>
<name><surname>Ballare&#xe9;</surname> <given-names>E</given-names></name>
<name><surname>Beck-Peccoz</surname> <given-names>P</given-names></name>
</person-group>. 
<article-title>Effects of hypothalamic neuropeptides on extracellular signal-regulated kinase (ERK1 and ERK2) cascade in human tumoral pituitary cells</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>2003</year>) <volume>88</volume>:<page-range>1692&#x2013;6</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jc.2002-021207</pub-id>, PMID: <pub-id pub-id-type="pmid">12679459</pub-id>
</mixed-citation>
</ref>
<ref id="B67">
<label>67</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lasolle</surname> <given-names>H</given-names></name>
<name><surname>Elsensohn</surname> <given-names>M-H</given-names></name>
<name><surname>Wierinckx</surname> <given-names>A</given-names></name>
<name><surname>Alix</surname> <given-names>E</given-names></name>
<name><surname>Bonnefille</surname> <given-names>C</given-names></name>
<name><surname>Vasiljevic</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Chromosomal instability in the prediction of pituitary neuroendocrine tumors prognosis</article-title>. <source>Acta Neuropathol Commun</source>. (<year>2020</year>) <volume>8</volume>:<fpage>190</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1186/s40478-020-01067-5</pub-id>, PMID: <pub-id pub-id-type="pmid">33168091</pub-id>
</mixed-citation>
</ref>
<ref id="B68">
<label>68</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rymuza</surname> <given-names>J</given-names></name>
<name><surname>Kober</surname> <given-names>P</given-names></name>
<name><surname>Rusetska</surname> <given-names>N</given-names></name>
<name><surname>Mossakowska</surname> <given-names>BJ</given-names></name>
<name><surname>Maksymowicz</surname> <given-names>M</given-names></name>
<name><surname>Nyc</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Transcriptomic classification of pituitary neuroendocrine tumors causing acromegaly</article-title>. <source>Cells</source>. (<year>2022</year>) <volume>11</volume>:<elocation-id>3846</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/cells11233846</pub-id>, PMID: <pub-id pub-id-type="pmid">36497102</pub-id>
</mixed-citation>
</ref>
<ref id="B69">
<label>69</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Tang</surname> <given-names>C</given-names></name>
<name><surname>Zhong</surname> <given-names>C</given-names></name>
<name><surname>Zhu</surname> <given-names>J</given-names></name>
<name><surname>Yuan</surname> <given-names>F</given-names></name>
<name><surname>Yang</surname> <given-names>J</given-names></name>
<name><surname>Xu</surname> <given-names>Y</given-names></name>
<etal/>
</person-group>. 
<article-title><italic>GNAS</italic> mutations suppress cell invasion by activating MEG3 in growth hormone&#x2013;secreting pituitary adenoma</article-title>. <source>Oncol Res</source>. (<year>2024</year>) <volume>32</volume>:<page-range>1079&#x2013;91</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.32604/or.2024.046007</pub-id>, PMID: <pub-id pub-id-type="pmid">38827318</pub-id>
</mixed-citation>
</ref>
<ref id="B70">
<label>70</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Park</surname> <given-names>C</given-names></name>
<name><surname>Yang</surname> <given-names>I</given-names></name>
<name><surname>Woo</surname> <given-names>J</given-names></name>
<name><surname>Kim</surname> <given-names>S</given-names></name>
<name><surname>Kim</surname> <given-names>J</given-names></name>
<name><surname>Kim</surname> <given-names>Y</given-names></name>
<etal/>
</person-group>. 
<article-title>Somatostatin (SRIF) receptor subtype 2 and 5 gene expression in growth hormone-secreting pituitary adenomas: the relationship with endogenous SRIF activity and response to octreotide</article-title>. <source>Endocr J</source>. (<year>2004</year>) <volume>51</volume>:<page-range>227&#x2013;36</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1507/endocrj.51.227</pub-id>, PMID: <pub-id pub-id-type="pmid">15118275</pub-id>
</mixed-citation>
</ref>
<ref id="B71">
<label>71</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Efstathiadou</surname> <given-names>ZA</given-names></name>
<name><surname>Bargiota</surname> <given-names>A</given-names></name>
<name><surname>Chrisoulidou</surname> <given-names>A</given-names></name>
<name><surname>Kanakis</surname> <given-names>G</given-names></name>
<name><surname>Papanastasiou</surname> <given-names>L</given-names></name>
<name><surname>Theodoropoulou</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Impact of gsp mutations in somatotroph pituitary adenomas on growth hormone response to somatostatin analogs: a meta-analysis</article-title>. <source>Pituitary</source>. (<year>2015</year>) <volume>18</volume>:<page-range>861&#x2013;7</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-015-0662-5</pub-id>, PMID: <pub-id pub-id-type="pmid">26115707</pub-id>
</mixed-citation>
</ref>
<ref id="B72">
<label>72</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Colao</surname> <given-names>A</given-names></name>
<name><surname>Ferone</surname> <given-names>D</given-names></name>
<name><surname>Lastoria</surname> <given-names>S</given-names></name>
<name><surname>Marzullo</surname> <given-names>P</given-names></name>
<name><surname>Cerbone</surname> <given-names>G</given-names></name>
<name><surname>Di Sarno</surname> <given-names>A</given-names></name>
<etal/>
</person-group>. 
<article-title>Prediction of efficacy of octreotide therapy in patients with acromegaly</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1996</year>) <volume>81</volume>:<page-range>2356&#x2013;62</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.81.6.8964877</pub-id>, PMID: <pub-id pub-id-type="pmid">8964877</pub-id>
</mixed-citation>
</ref>
<ref id="B73">
<label>73</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>de Herder</surname> <given-names>WW</given-names></name>
<name><surname>Taal</surname> <given-names>HR</given-names></name>
<name><surname>Uitterlinden</surname> <given-names>P</given-names></name>
<name><surname>Feelders</surname> <given-names>RA</given-names></name>
<name><surname>Janssen</surname> <given-names>JA</given-names></name>
<name><surname>van der Lely</surname> <given-names>AJ</given-names></name>
</person-group>. 
<article-title>Limited predictive value of an acute test with subcutaneous octreotide for long-term IGF-I normalization with Sandostatin LAR in acromegaly</article-title>. <source>Eur J Endocrinol</source>. (<year>2005</year>) <volume>153</volume>:<fpage>67</fpage>&#x2013;<lpage>71</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje.1.01935</pub-id>, PMID: <pub-id pub-id-type="pmid">15994747</pub-id>
</mixed-citation>
</ref>
<ref id="B74">
<label>74</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Pokrajac</surname> <given-names>A</given-names></name>
<name><surname>Claridge</surname> <given-names>AG</given-names></name>
<name><surname>Shakoor</surname> <given-names>SK</given-names></name>
<name><surname>Trainer</surname> <given-names>PJ</given-names></name>
</person-group>. 
<article-title>The octreotide test dose is not a reliable predictor of the subsequent response to somatostatin analogue therapy in patients with acromegaly</article-title>. <source>Eur J Endocrinol</source>. (<year>2006</year>) <volume>154</volume>:<page-range>267&#x2013;74</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1530/eje.1.02073</pub-id>, PMID: <pub-id pub-id-type="pmid">16452540</pub-id>
</mixed-citation>
</ref>
<ref id="B75">
<label>75</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Chiloiro</surname> <given-names>S</given-names></name>
<name><surname>Giampietro</surname> <given-names>A</given-names></name>
<name><surname>Giamb&#xf2;</surname> <given-names>P</given-names></name>
<name><surname>Costanza</surname> <given-names>F</given-names></name>
<name><surname>Mattogno</surname> <given-names>PP</given-names></name>
<name><surname>Lauretti</surname> <given-names>L</given-names></name>
<etal/>
</person-group>. 
<article-title>IGF-I levels during standard lanreotide dose predicts biochemical outcome of high-frequency regimen in acromegaly</article-title>. <source>Pituitary</source>. (<year>2024</year>) <volume>28</volume>:<elocation-id>7</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-024-01479-9</pub-id>, PMID: <pub-id pub-id-type="pmid">39724447</pub-id>
</mixed-citation>
</ref>
<ref id="B76">
<label>76</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Kim</surname> <given-names>E</given-names></name>
<name><surname>Sohn</surname> <given-names>S</given-names></name>
<name><surname>Lee</surname> <given-names>M</given-names></name>
<name><surname>Park</surname> <given-names>C</given-names></name>
<name><surname>Jung</surname> <given-names>J</given-names></name>
<name><surname>Park</surname> <given-names>S</given-names></name>
</person-group>. 
<article-title>Effect of <italic>gsp</italic> oncogene on somatostatin receptor subtype 1 and 2 mRNA levels in GHRH-responsive GH3 cells</article-title>. <source>Pituitary</source>. (<year>2005</year>) <volume>8</volume>:<page-range>155&#x2013;62</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s11102-005-5245-4</pub-id>, PMID: <pub-id pub-id-type="pmid">16379030</pub-id>
</mixed-citation>
</ref>
<ref id="B77">
<label>77</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Fougner</surname> <given-names>SL</given-names></name>
<name><surname>Borota</surname> <given-names>OC</given-names></name>
<name><surname>Berg</surname> <given-names>JP</given-names></name>
<name><surname>Hald</surname> <given-names>JK</given-names></name>
<name><surname>Ramm-Pettersen</surname> <given-names>J</given-names></name>
<name><surname>Bollerslev</surname> <given-names>J</given-names></name>
</person-group>. 
<article-title>The clinical response to somatostatin analogues in acromegaly correlates to the somatostatin receptor subtype 2a protein expression of the adenoma</article-title>. <source>Clin Endocrinol (Oxf)</source>. (<year>2008</year>) <volume>68</volume>:<page-range>458&#x2013;65</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/j.1365-2265.2007.03065.x</pub-id>, PMID: <pub-id pub-id-type="pmid">17941904</pub-id>
</mixed-citation>
</ref>
<ref id="B78">
<label>78</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Corbetta</surname> <given-names>S</given-names></name>
<name><surname>Ballar&#xe9;</surname> <given-names>E</given-names></name>
<name><surname>Mantovani</surname> <given-names>G</given-names></name>
<name><surname>Lania</surname> <given-names>A</given-names></name>
<name><surname>Losa</surname> <given-names>M</given-names></name>
<name><surname>Di Blasio</surname> <given-names>AM</given-names></name>
<etal/>
</person-group>. 
<article-title>Somatostatin receptor subtype 2 and 5 in human GH-secreting pituitary adenomas: analysis of gene sequence and mRNA expression</article-title>. <source>Eur J Clin Invest</source>. (<year>2001</year>) <volume>31</volume>:<page-range>208&#x2013;14</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1046/j.1365-2362.2001.00786.x</pub-id>, PMID: <pub-id pub-id-type="pmid">11264647</pub-id>
</mixed-citation>
</ref>
<ref id="B79">
<label>79</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Barlier</surname> <given-names>A</given-names></name>
<name><surname>Pellegrini-Bouiller</surname> <given-names>I</given-names></name>
<name><surname>Gunz</surname> <given-names>G</given-names></name>
<name><surname>Zamora</surname> <given-names>AJ</given-names></name>
<name><surname>Jaquet</surname> <given-names>P</given-names></name>
<name><surname>Enjalbert</surname> <given-names>A</given-names></name>
</person-group>. 
<article-title>Impact of <italic>gsp</italic> oncogene on the expression of genes coding for G<sub>s</sub>&#x3b1;, Pit-1, G<sub>i</sub>2&#x3b1;, and somatostatin receptor 2 in human somatotroph adenomas: involvement in octreotide sensitivity</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1999</year>) <volume>84</volume>:<page-range>2759&#x2013;65</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.84.8.5919</pub-id>, PMID: <pub-id pub-id-type="pmid">10443675</pub-id>
</mixed-citation>
</ref>
<ref id="B80">
<label>80</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rick</surname> <given-names>J</given-names></name>
<name><surname>Jahangiri</surname> <given-names>A</given-names></name>
<name><surname>Flanigan</surname> <given-names>PM</given-names></name>
<name><surname>Chandra</surname> <given-names>A</given-names></name>
<name><surname>Kunwar</surname> <given-names>S</given-names></name>
<name><surname>Blevins</surname> <given-names>L</given-names></name>
<etal/>
</person-group>. 
<article-title>Growth hormone and prolactin-staining tumors causing acromegaly: a retrospective review of clinical presentations and surgical outcomes</article-title>. <source>J Neurosurg</source>. (<year>2019</year>) <volume>131</volume>:<page-range>147&#x2013;53</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.3171/2018.4.Jns18230</pub-id>, PMID: <pub-id pub-id-type="pmid">30215558</pub-id>
</mixed-citation>
</ref>
<ref id="B81">
<label>81</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Lv</surname> <given-names>L</given-names></name>
<name><surname>Jiang</surname> <given-names>Y</given-names></name>
<name><surname>Yin</surname> <given-names>S</given-names></name>
<name><surname>Hu</surname> <given-names>Y</given-names></name>
<name><surname>Chen</surname> <given-names>C</given-names></name>
<name><surname>Ma</surname> <given-names>W</given-names></name>
<etal/>
</person-group>. 
<article-title>Mammosomatotroph and mixed somatotroph-lactotroph adenoma in acromegaly: a retrospective study with long-term follow-up</article-title>. <source>Endocrine</source>. (<year>2019</year>) <volume>66</volume>:<page-range>310&#x2013;8</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s12020-019-02029-1</pub-id>, PMID: <pub-id pub-id-type="pmid">31368083</pub-id>
</mixed-citation>
</ref>
<ref id="B82">
<label>82</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Petersenn</surname> <given-names>S</given-names></name>
<name><surname>Fleseriu</surname> <given-names>M</given-names></name>
<name><surname>Casanueva</surname> <given-names>FF</given-names></name>
<name><surname>Giustina</surname> <given-names>A</given-names></name>
<name><surname>Biermasz</surname> <given-names>N</given-names></name>
<name><surname>Biller</surname> <given-names>BMK</given-names></name>
<etal/>
</person-group>. 
<article-title>Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement</article-title>. <source>Nat Rev Endocrinol</source>. (<year>2023</year>) <volume>19</volume>:<page-range>722&#x2013;40</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41574-023-00886-5</pub-id>, PMID: <pub-id pub-id-type="pmid">37670148</pub-id>
</mixed-citation>
</ref>
<ref id="B83">
<label>83</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Asa</surname> <given-names>SL</given-names></name>
<name><surname>Ezzat</surname> <given-names>S</given-names></name>
</person-group>. 
<article-title>An update on pituitary neuroendocrine tumors leading to acromegaly and gigantism</article-title>. <source>J Clin Med</source>. (<year>2021</year>) <volume>10</volume>:<fpage>2254</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/jcm10112254</pub-id>, PMID: <pub-id pub-id-type="pmid">34067494</pub-id>
</mixed-citation>
</ref>
<ref id="B84">
<label>84</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Boothroyd</surname> <given-names>CV</given-names></name>
<name><surname>Grimmond</surname> <given-names>SM</given-names></name>
<name><surname>Cameron</surname> <given-names>DP</given-names></name>
<name><surname>Hayward</surname> <given-names>NK</given-names></name>
</person-group>. 
<article-title>G protein mutations in tumours of the pituitary, parathyroid and endocrine pancreas</article-title>. <source>Biochem Biophys Res Commun</source>. (<year>1995</year>) <volume>211</volume>:<page-range>1063&#x2013;70</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1006/bbrc.1995.1919</pub-id>, PMID: <pub-id pub-id-type="pmid">7598693</pub-id>
</mixed-citation>
</ref>
<ref id="B85">
<label>85</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Drews</surname> <given-names>RT</given-names></name>
<name><surname>Gravel</surname> <given-names>RA</given-names></name>
<name><surname>Collu</surname> <given-names>R</given-names></name>
</person-group>. 
<article-title>Identification of G protein &#x3b1; subunit mutations in human growth hormone (GH)- and GH/prolactin-secreting pituitary tumors by single-strand conformation polymorphism (SSCP) analysis</article-title>. <source>Mol Cell Endocrinol</source>. (<year>1992</year>) <volume>87</volume>:<page-range>125&#x2013;9</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/0303-7207(92)90240-7</pub-id>, PMID: <pub-id pub-id-type="pmid">1446784</pub-id>
</mixed-citation>
</ref>
<ref id="B86">
<label>86</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Kober</surname> <given-names>P</given-names></name>
<name><surname>Rymuza</surname> <given-names>J</given-names></name>
<name><surname>Baluszek</surname> <given-names>S</given-names></name>
<name><surname>Maksymowicz</surname> <given-names>M</given-names></name>
<name><surname>Nyc</surname> <given-names>A</given-names></name>
<name><surname>Mossakowska</surname> <given-names>BJ</given-names></name>
<etal/>
</person-group>. 
<article-title>DNA methylation pattern in somatotroph pituitary neuroendocrine tumors</article-title>. <source>Neuroendocrinology</source>. (<year>2024</year>) <volume>114</volume>:<fpage>51</fpage>&#x2013;<lpage>63</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1159/000533692</pub-id>, PMID: <pub-id pub-id-type="pmid">37699356</pub-id>
</mixed-citation>
</ref>
<ref id="B87">
<label>87</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Romanet</surname> <given-names>P</given-names></name>
<name><surname>Galluso</surname> <given-names>J</given-names></name>
<name><surname>Kamenicky</surname> <given-names>P</given-names></name>
<name><surname>Hage</surname> <given-names>M</given-names></name>
<name><surname>Theodoropoulou</surname> <given-names>M</given-names></name>
<name><surname>Roche</surname> <given-names>C</given-names></name>
<etal/>
</person-group>. 
<article-title>Somatotroph tumors and the epigenetic status of the <italic>GNAS</italic> locus</article-title>. <source>Int J Mol Sci</source>. (<year>2021</year>) <volume>22</volume>:<elocation-id>7570</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/ijms22147570</pub-id>, PMID: <pub-id pub-id-type="pmid">34299200</pub-id>
</mixed-citation>
</ref>
<ref id="B88">
<label>88</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Clementi</surname> <given-names>E</given-names></name>
<name><surname>Malgaretti</surname> <given-names>N</given-names></name>
<name><surname>Meldolesi</surname> <given-names>J</given-names></name>
<name><surname>Taramelli</surname> <given-names>R</given-names></name>
</person-group>. 
<article-title>A new constitutively activating mutation of the Gs protein &#x3b1; subunit-<italic>gsp</italic> oncogene is found in human pituitary tumours</article-title>. <source>Oncogene</source>. (<year>1990</year>) <volume>5</volume>:<page-range>1059&#x2013;61</page-range>., PMID: <pub-id pub-id-type="pmid">2115641</pub-id>
</mixed-citation>
</ref>
<ref id="B89">
<label>89</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Kan</surname> <given-names>B</given-names></name>
<name><surname>Esapa</surname> <given-names>C</given-names></name>
<name><surname>Sipahi</surname> <given-names>T</given-names></name>
<name><surname>Nacar</surname> <given-names>C</given-names></name>
<name><surname>&#xd6;zer</surname> <given-names>F</given-names></name>
<name><surname>Sayhan</surname> <given-names>NB</given-names></name>
<etal/>
</person-group>. 
<article-title>G protein mutations in pituitary tumors: a study on Turkish patients</article-title>. <source>Pituitary</source>. (<year>2003</year>) <volume>6</volume>:<fpage>75</fpage>&#x2013;<lpage>80</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1023/b:pitu.0000004797.89592.5e</pub-id>, PMID: <pub-id pub-id-type="pmid">14703016</pub-id>
</mixed-citation>
</ref>
<ref id="B90">
<label>90</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Ballare&#xe9;</surname> <given-names>E</given-names></name>
<name><surname>Mantovani</surname> <given-names>S</given-names></name>
<name><surname>Lania</surname> <given-names>A</given-names></name>
<name><surname>Di Blasio</surname> <given-names>AM</given-names></name>
<name><surname>Vallar</surname> <given-names>L</given-names></name>
<name><surname>Spada</surname> <given-names>A</given-names></name>
</person-group>. 
<article-title>Activating mutations of the G<sub>s</sub>&#x3b1; gene are associated with low levels of Gs&#x3b1; protein in growth hormone-secreting tumors</article-title>. <source>J Clin Endocrinol Metab</source>. (<year>1998</year>) <volume>83</volume>:<page-range>4386&#x2013;90</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/jcem.83.12.5354</pub-id>, PMID: <pub-id pub-id-type="pmid">9851782</pub-id>
</mixed-citation>
</ref>
<ref id="B91">
<label>91</label>
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Bi</surname> <given-names>WL</given-names></name>
<name><surname>Greenwald</surname> <given-names>NF</given-names></name>
<name><surname>Ramkissoon</surname> <given-names>SH</given-names></name>
<name><surname>Abedalthagafi</surname> <given-names>M</given-names></name>
<name><surname>Coy</surname> <given-names>SM</given-names></name>
<name><surname>Ligon</surname> <given-names>KL</given-names></name>
<etal/>
</person-group>. 
<article-title>Clinical identification of oncogenic drivers and copy-number alterations in pituitary tumors</article-title>. <source>Endocrinology</source>. (<year>2017</year>) <volume>158</volume>:<page-range>2284&#x2013;91</page-range>. doi:&#xa0;<pub-id pub-id-type="doi">10.1210/en.2016-1967</pub-id>, PMID: <pub-id pub-id-type="pmid">28486603</pub-id>
</mixed-citation>
</ref>
</ref-list>
<fn-group>
<fn id="n1" fn-type="custom" custom-type="edited-by">
<p>Edited by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2197992">Raluca Alexandra Trifanescu</ext-link>, Carol Davila University of Medicine and Pharmacy, Romania</p></fn>
<fn id="n2" fn-type="custom" custom-type="reviewed-by">
<p>Reviewed by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2209472">Laura C. Hern&#xe1;ndez-Ram&#xed;rez</ext-link>, National Autonomous University of Mexico, Mexico</p>
<p><ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2344182">Flavia Costanza</ext-link>, Agostino Gemelli University Polyclinic (IRCCS), Italy</p></fn>
</fn-group>
<fn-group>
<fn fn-type="abbr" id="abbrev1">
<label>Abbreviations:</label>
<p>cAMP, cyclic adenosine monophosphate; CI, confidence interval; CREB cAMP, response element-binding protein; GH, growth hormone; GHRH, growth hormone-releasing hormone; GPCR, G protein-coupled receptor; Gs&#x3b1;, stimulatory G protein alpha subunit; IGF-1, insulin-like growth factor 1; IQR, interquartile range; MSA, mammosomatotroph adenoma; MSLA, mixed somatotroph-lactotroph adenoma; OGTT, oral glucose tolerance testing; PACT, profiling of actionable cancer targets; PDE, phosphodiesterase; Q1, first quartile; Q3, third quartile; SD, standard deviation; SRL, somatostatin receptor ligand; SSTR2, somatostatin receptor 2; SSTR5, somatostatin receptor 5; ULN, upper limit of normal.</p>
</fn>
</fn-group>
</back>
</article>