Rethinking pN1 Disease in Non-Small Cell Lung Cancer: Anatomical Subclassification, Surgical Extent, and Survival...

Background: Pathological N1 (pN1) non-small cell lung cancer (NSCLC) presents variable survival; yet, the TNM system lacks N1 subclassification. While studies focus on numerical nodal burden, the prognostic impact of anatomical location remains unclear. Surgically, completion lobectomy is advised after sublobar resection for N1-positive disease. However, for hilar/interlobar involvement-where residual lymphatic pathways remain post-lobectomy-extension to pneumonectomy is rarely performed, raising uncertainty about the optimal extent of resection in different pN1 subgroups. Methods: This retrospective study evaluated 150 patients with pN1 NSCLC who underwent curative-intent anatomical lung resection and systematic nodal dissection (2012-2023). The follow-up period extended from the date of surgery to death or last follow-up, with survival status assessed until March 2026. Clinicopathological variables, including anatomical N1 level, nodal burden, tumor characteristics, and surgical extent, were analyzed alongside survival outcomes. Results: Peripheral N1 involvement (stations 12-14) yielded significantly longer survival than hilar/interlobar metastasis (stations 10-11) (p = 0.019). Nodal count and multiple-station involvement did not impact survival. Age (HR: 1.036, p = 0.026) and interlobar station 11 pN1 positivity (HR: 1.912, p = 0.044) emerged as independent negative prognostic factors for overall survival. Perineural invasion worsened survival in Stage III disease. Extended resections offered no survival benefit and worsened outcomes in hilar/interlobar disease. Conclusions: The anatomical level of N1 metastasis is a key prognostic factor in pN1 NSCLC. Standard lobectomy appears sufficient across all subgroups, including hilar/interlobar disease, while extended resections do not improve survival. Future studies should clarify systemic/adjuvant treatment strategies.