The incidence and mortality of lung cancer has been increasing over the past decades (1, 2). For stage IA non-small cell lung cancer (NSCLC), surgery remains the standard treatment method (2). In traditional concepts, lobectomy is the standard surgical procedure for these patients. However, in recent years, with the introduction of minimally invasive concepts, how to protect lung function as much as possible under the same survival efficacy has received attention from thoracic surgeons around the world (3). For stage IA1-2 (T1a-bN0M0) NSCLC, segmentectomy has been proven to have better perioperative efficacy, lung function protection, and noninferior survival efficacy compared with lobectomy (4–6). However, whether this conclusion is valid in stage IA3 NSCLC remains controversial in clinical practice.

To clarify this debate, several studies have been conducted in the past decade. Ogawa et al.’s and Deng et al.’s studies suggested that lobectomy achieved better overall survival (OS) and disease-free survival (DFS) than segmentectomy (7, 8). However, Forster et al.’s and Wang et al.’s studies did not find a survival advantage in the lobectomy group, and there were more complications in the lobectomy group (9, 10). Kamigaichi et al.’s and Yamashita et al.’s studies did not find any differences in the efficacy of survival and safety between the two groups (11, 12).

To clarify this controversy, we compared the survival and perioperative outcomes between lobectomy and segmentectomy procedures.

For a long time, lobectomy is the standard surgical procedure for stage I NSCLC (25). In recent years, some evidence has shown that segmentectomy has better outcomes than lobectomy in stage IA1-2 (T1a-bN0M0) NSCLC (4–6). However, whether this conclusion is valid in stage IA3 (T1cN0M0) NSCLC remains controversial in clinical practice. This meta-analysis compared the two surgical procedures in IA3 (T1cN0M0) NSCLC. The results suggested that the lobectomy group achieved better OS and DFS. The survival advantages in the lobectomy group increased over the survival time. More lymph nodes dissection, intraoperative blood loss and complications were found in lobectomy group.

Better survival is the main advantage with lobectomy, and this advantage will increase with the prolongation of survival. The OSR-5y is 71% in the lobectomy group and 57% in the segmentectomy group. Tendency for survival advantage were supported by six included studies (7–9, 11, 12, 21). Yu et al.’s study based on 9580 patients also suggested that lobectomy and complete lymph node dissection should be the recommended standard of care for patients with stage IA3 NSCLC (26). Three reasons may explain this result: (1) Farther tumor margins reduce the possibility of local tumor recurrence in the lobectomy group (8); (2) More lymph node dissection numbers reduce the lymph node recurrence in the lobectomy group (12, 24); (3) Some N1 lymph nodes were not removed in the segmentectomy group, which may affect the staging judgment. Higher actual pathologic staging may affect the prognosis of patients in the segmentectomy group (7). Meanwhile, the survival advantage of lobectomy was proved in all subgroups according to the published year, nation, stage, and data sources. Therefore, we believe that lobectomy should be performed for stage IA3 NSCLC, which not only meets the requirements of the guidelines but also meets the survival needs of patients

Surgical safety is another important indicator for evaluating surgery. Lower intraoperative and postoperative complications often indicate better quality of life and lower costs (27). In this study, more operative time and intraoperative blood loss were found during lobectomy procedure, which is consistent with the actual situation in our surgeries. From the specific data, an average bleeding increment of 50.22 ml and a 4.17 minutes surgical time increment per surgery are acceptable by most patients and surgeons. Meanwhile, more total complications were found in the lobectomy group (RR: 1.28 [1.04~1.59]), which is also in line with our actual postoperative situation. Similar results were also reported in the Ichinose et al.’s study based on 59663 patients (28). However, no significant difference was found in the comparison of all single complications. Pulmonary complications and atrial fibrillation are the two most common complications after lung surgery, with incidence rates of approximately 20% in each group, respectively. Meanwhile, age, operation time and number of lymph node dissected during operation are independent risk factors affecting postoperative complications (29). Thus, although lobectomy may result in better survival outcomes, its more frequent complications need to be taken seriously.

The main consideration for choosing segmentectomy is to protect lung function as much as possible. For NSCLC up to 2 cm, Bao et al. (30) and Ji et al. (29) reported that segmentectomy shows less loss of lung function than lobectomy. Xu et al. (31) suggested that segmentectomy is helpful to minimize the loss of FVC, but not FEV1 or DLCO. However, for tumors of this size (2-3 cm), in order to ensure sufficient distance between the tumor margins, segmental resection of lung tissue is often larger than single lung segment, and even requires combined segmental resection. In these patients, it is controversial whether lung function could be protected, as compared to lobectomy (32). In the current study, due to database limitations, no analysis results related to lung function protection have been obtained, which is important in the future research.

There are still some limitations in the study. First, all retrieved databases are in English, which might result in some non-English published papers that meet the standards not being included. Second, the evidence level of all results is low or very low, which may reduce the credibility of the conclusion. Third, data of lung function was lacking in all the included studies, and it is important to compare the two surgery procedures. Fourth, there are two forms of staging: clinical staging and pathological staging, which might increase the heterogeneity. Fifth, the data sources are different because some of the data were from large databases and some were from single centers, which might increase the heterogeneity.

In summary, lobectomy appeared to be the better choice for patients with stage IA3 NSCLC with better survival (OS and DFS). The survival advantages in the lobectomy group increased over the survival time. Meanwhile, more attention should be given to the control of postoperative complications. However, due to insufficient evidence of the results, large sample RCTs need to be conducted to confirm the conclusion.

The original contributions presented in the study are included in the article/ Supplementary Material . Further inquiries can be directed to the corresponding author.

WZ: Conceptualization, Data curation, Formal Analysis, Methodology, Resources, Software, Writing – original draft, Writing – review & editing. SC: Conceptualization, Data curation, Formal Analysis, Investigation, Methodology, Writing – original draft. XL: Conceptualization, Data curation, Formal Analysis, Investigation, Methodology, Software, Writing – original draft. HC: Conceptualization, Data curation, Formal Analysis, Investigation, Methodology, Software, Writing – original draft. RH: Conceptualization, Data curation, Formal Analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing.