Surgery after neoadjuvant therapy in patients with resectable stage IIIB/N2 non-small cell lung cancer.

Objective: This study evaluates the role of surgery in selected stage IIIB/N2 non-small cell lung cancer (NSCLC) patients within a multimodal treatment approach. We focused on the impact of mediastinal downstaging, local tumor invasion, and postoperative complications on survival outcomes.

Methods: A retrospective analysis was conducted on 1752 NSCLC patients who underwent surgery between 2010 and 2016. Among them, 49 patients with clinical stage IIIB/N2 NSCLC were identified based on single-station, non-bulky N2 disease confirmed by invasive staging and anatomically resectable tumors. Patients were grouped by T stage and mediastinal downstaging status following neoadjuvant therapy. Survival outcomes were analyzed using Kaplan-Meier and Cox regression models.

Results: The overall 5-year survival (OS) rate was 29.2% (median 23 months), and the 5-year disease-free survival (DFS) rate was 22.0% (median 12.4 months). While patients with non-invasive T3 tumors had better OS and DFS than those with invasive T3 or T4 tumors, the differences were not statistically significant. Mediastinal downstaging was associated with improved OS (p = 0.049). Multivariate analysis identified local tumor invasion (HR: 2.15, p = 0.045) and early postoperative complications (HR: 2.93, p = 0.011) as independent predictors of worse OS.

Conclusions: Surgical resection may be a viable option in highly selected cIIIB/N2 NSCLC patients-particularly those who respond well to neoadjuvant therapy and are anatomically resectable. However, tumor invasion and postoperative complications negatively affect survival. These findings underscore the importance of precise patient selection and perioperative management. Further prospective studies are needed to validate the role of surgery in this subset, especially in the context of evolving systemic therapies.