Long-term outcomes of upfront surgery in patients with resectable pathological N2 non-small-cell lung cancer

OBJECTIVES: Although the standard treatment for pathological N2 (pN2) non-small-cell lung cancer (NSCLC) patients is definitive chemoradiation, surgery can be beneficial for resectable pN2 disease. Herein, we report the long-term clinical outcomes of upfront surgery followed by adjuvant treatment for selected patients with resectable pN2 disease. METHODS: We performed a retrospective analysis of clinical outcomes for patients with pN2 disease who underwent surgery as the first-line therapy. Multivariable Cox regression analysis was used to identify the significant factors for overall survival (OS) and recurrence-free survival. RESULTS: From 2004 to 2015, a total of 706 patients with pN2 NSCLC underwent complete anatomical resection at our institution. The patients' clinical N stages were cN0, 308 (43.6%); cN1, 123 (17.4%) and cN2, 275 (39.0%). Adjuvant chemotherapy, radiotherapy and chemoradiotherapy were administered to 169 (23.9%), 115 (17.4%) and 299 patients (42.4%), respectively. With a median follow-up of 40 months, the respective median time and 5-year rate of OS were 52 months and 44.7%. According to subdivided pN2 descriptors, the median OS time was 80, 53 and 37 months for patients with pN2a1, pN2a2 and pN2b, respectively. Adjuvant chemotherapy was a significant prognostic factor for both OS [hazard ratio (HR) 0.39, 95% confidence interval (CI) 0.28-0.52; P < 0.001] and recurrence-free survival (HR 0.42, 95% CI 0.30-0.58; P < 0.001). CONCLUSIONS: Upfront surgery followed by adjuvant therapy for resectable N2 disease showed favourable outcomes compared to those reported in previous studies. Adjuvant chemotherapy is essential to improve the prognosis for patients undergoing upfront surgery for N2 disease.