This study assesses the effect of postoperative radiotherapy on survival outcomes in patients diagnosed with stage pIIIA-N2 non-small cell lung cancer (NSCLC) after sublobar resection. Data of patients with stage pIIIA-N2 NSCLC who underwent sublobar resection were extracted from the Surveillance, Epidemiology, and End Results database spanning from 2000 to 2020. Patients were divided into 2 groups: postoperative radiotherapy and observation. Cancer-specific survival (CSS) and overall survival (OS) were analyzed and compared between the 2 groups. A total of 444 patients were included in the study, with 210 (47.3%) receiving postoperative radiotherapy and 234 (52.7%) with observation. The CSS (hazard ratio [HR] = 0.99, 95% confidence interval [CI]: 0.78-1.26
P = .926) and OS (HR = 0.93, 95% CI: 0.75-1.15
P = .512) did not show significant differences between the postoperative radiotherapy and observation groups. Subgroup analysis of patients receiving postoperative chemotherapy revealed comparable CSS (HR = 1.24, 95% CI: 0.89-1.71
P = .203) and OS (HR = 1.12, 95% CI: 0.85-1.49
P = .425) between the 2 groups. Similarly, for patients without postoperative chemotherapy, CSS (HR = 1.11, 95% CI: 0.66-1.84
P = .699) and OS (HR = 1.08, 95% CI: 0.68-1.71
P = .740) were not significantly different between the 2 groups. Postoperative radiotherapy does not improve survival in patients with stage pIIIA-N2 NSCLC following sublobar resection.