Survival outcome of upfront surgery for clinical single-station N2 non-small cell lung cancer

Background Pathological N2 (pN2) non-small cell lung cancer (NSCLC) is diverse; its treatment depends on the clinical N (cN) status. We aimed to determine the efficacy of upfront surgery for cN2pN2 NSCLC. Methods The study included 43 cN2pN2 NSCLC patients who underwent upfront surgery at the Shizuoka Cancer Center between 2002 and 2017. Survival outcome, focusing on cN2 status, was retrospectively investigated. Mediastinal lymph nodes were pre-operatively evaluated using computed tomography and positron emission tomography. Surgical eligibility criteria included single-station cN2. N2 with N1 and skip N2 were defined as N2 with and without ipsilateral hilar lymph node metastasis, respectively. A platinum-doublet regimen was used for adjuvant chemotherapy. Survival curves were analysed using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazard regression model. Results Clinical-skip N2 and cN2 with N1 cases included 22 and 21 patients, respectively. Twenty-three patients received adjuvant chemotherapy. The median follow-up duration was 73 months. Clinical-skip N2 had a significantly better 5-year recurrence-free survival (RFS) than cN2 with N1 (58.3 vs 28.6%, P = 0.038) and was an independent favorable RFS predictor. Recurrence within 18 months occurred in 71% of cN2 with N1 cases. Five-year overall survival and RFS rates in patients receiving adjuvant chemotherapy vs those without adjuvant chemotherapy were 82.2 vs 41.9% (P = 0.019) and 56.5 vs 28.0% (P = 0.049), respectively. Conclusions Clinical-skip N2 had an excellent prognosis, and upfront surgery was acceptable. Conversely, upfront surgery followed by chemotherapy is not recommended for cN2 with N1 patients because of early recurrence. Upfront surgery followed by adjuvant chemotherapy for c-skip N2 showed an excellent prognosis in a retrospective analysis of patients with single-station cN2 non-small cell lung cancer.