Surgery for advanced-stage non-small cell lung cancer: lobectomy or sub-lobar resection?

Background: Metastatic non-small cell lung cancer (NSCLC) has many comorbidities, such as chronic obstructive pulmonary disease, coronary heart disease, and older age-related comorbidities. A survival benefit was observed in such patients who underwent surgery for selected oligometastatic disease. However, to the best of our knowledge, there is no evidence to support whether lobectomy (compared with sub-lobar resection) would further prolong these patients' lives. Methods: Patients with metastatic NSCLC who underwent primary tumor resection were identified from the Surveillance, Epidemiology, and End Results (SEER) database and then divided into lobectomy and sub-lobar resection groups. Propensity score matching (PSM, 1:1) was performed to match the baseline characteristics of the two groups. Cancer-specific survival (CSS) was estimated. Results: In total, 24,268 patients with metastatic NSCLC were identified; 4,114 (16.95%) underwent primary tumor surgery, and of these, 2,045 (49.71%) underwent lobectomy and 1,766 (42.93%) underwent sub-lobar resection. After PSM, 644 patients in each group were included. Lobectomy was independently correlated with longer median CSS time [hazards ratio (HR): 0.70, 95% confidence interval (CI): 0.61-0.80, P<0.001]. The 1, 2, and 3-year survival rates after PSM also favored the lobectomy group. However, no significant survival difference was found for wedge resection and segmentectomy ( HR: 0.96, 95% CI: 0.70-1.31, P=0.490). The 1-, 2-, and 3-year survival rates after PSM also exhibited no difference within the sub-lobar group. We explored whether lymph node dissection would provide additional survival benefits for stage IV NSCLC patients. According to the multivariate Cox analysis of the matched population, lymph node dissection was independently associated with better CSS (HR: 0.76, 95% CI: 0.66-0.88, P<0.001) and overall survival (OS) (HR: 0.74, 95% CI: 0.65-0.86, P<0.001). We confirmed this result in the different types of surgery and found that the lymph node dissection group consistently had better survival outcomes both in the lobectomy group and sub-lobar resection population. According to the subgroup analysis, with the exception of stage T4 and brain metastatic patients, all of the patient subtypes exhibited greater benefit from lobectomy than sub-lobar resection. Conclusions: Lobectomy has a greater survival benefit in metastatic NSCLC patients compared with sublobar resection when radical treatment of primary site was indicated.