Supplementary Material for: Lobectomy with lymph node dissection benefits N3 stage non-small cell lung cancer patients: a population-based study

Introduction: There remains controversies about the role of surgery for N3 stage non-small cell lung cancer (NSCLC) patients. Methods: N3 stage NSCLC patients were identified from the US National Cancer Institute Surveillance, Epidemiology, and End Results database (2010–2020). Survival analysis and multivariate regression models were used to adjust covariates and analyze factors associated with survival. Propensity score matching was used to balance selection bias. Results: Of 6473 included patients, 121 received treatment that included lobectomy with mediastinal lymph node dissection. Overall survival (OS) was significantly prolonged in the lobectomy group than in the non-surgery group [median survival time (MST): 57 vs 16 months; Log-rank p<0.001]. A total of 403 patients were matched, and OS was significant longer in lobectomy group (MST: 51 vs 16 months; Log-rank p<0.001). Multivariate regression analyses indicated that lobectomy was independently associated with improved OS [hazard ratio (HR) 0.398, 95% confidence interval (CI) 0.302–0.526; p<0.001] and lung cancer-specific death (LCSD) [subhazard ratio (SHR) 0.343, 95%CI 0.249–0.474; p<0.001]. Conclusion: Compared with non-surgical treatment modalities, lobectomy with lymph node dissection was associated with improved OS and LCSD in selected N3 stage NSCLC patients.