AUTHOR=Hu Xiao Mu , Nie Xiao yu , Xu Kai lun , Wang Yin , Tang Feng , Du Zun guo , Xiong Ji 

TITLE=H3K27M Mutation Doesn’t Mean Worse Prognosis in Old Patients

JOURNAL=Frontiers in Oncology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.912166

DOI=10.3389/fonc.2022.912166

ISSN=2234-943X

ABSTRACT=Objective: Diffuse midline glioma (DMG), H3K27 altered is a new entity that has become widely recognized. However, studies concerning DMG in adult patients remains rare. We did a retrospective study covering the largest amount of patients to date to analyze the clinicopathological characteristics of diffuse glioma in midline structures of adult. 
Methods: We reviewed 108 cases of adult DMG, collected their clinical data along with pathological results including H3K27 mutation. Summarized their features and the connection with overall survival in different age groups.
Results: Among 108 cases, 79 tumors were located at the thalamus. 38 patients had H3K27M mutation, whose average age were 35.7. The median overall survival of H3K27M-mutant gliomas and the 80 H3K27M wild-type gliomas were both 12 months. For young patients (age≤35), The median survival time of the H3K27M-mutant was 18 months, while that of the H3K27M wild-type was 37 months. For older patients (age>35), the median survival time of the H3K27M-mutant was 16 months, while that of the H3K27M wild-type was 13 months. Other clinicopathological factors including sex, tumor location, approach of surgery, histological grade, ATRX and P53 were statistically irrelevant with prognosis.
Conclusion: The DMG in adults mainly occurred in the thalamus. H3K27M mutations tend to happen more frequently in young adults, and this genetic alteration results in a worse outcome only in young patients (≤35). For old patients, age is the only independent prognostic factor. Patients underwent different surgical operations including biopsy, subtotal resection and total resection had similar prognosis.