Long-term outcomes following neoadjuvant or adjuvant chemoradiotherapy for stage I–IIIA non-small cell lung cancer: a propensity-matched analysis

BACKGROUND: This study aimed to evaluate the long-term survival outcomes of patients undergoing neoadjuvant chemoradiotherapy or adjuvant chemoradiotherapy for T1-4N0-1M0 disease. METHODS: Patients with pT1-4N0-1M0 between 2010 and 2015 who received pre- or postoperative (R0 resection) chemoradiotherapy were identified. The exclusion criteria included N2 or M1 disease, immunotherapy, and targeted therapy. The staging was recalculated according to the new 8th edition TNM classification. Survival and predictors were assessed using Kaplan-Meier and multivariate Cox proportional-hazards model. Propensity-score matching with a ratio of 2:1 was performed to reduce bias in various clinicopathological factors. RESULTS: Of the 1,769 patients who met the inclusion criteria, 407 and 814 were included in the neoadjuvant and adjuvant chemoradiotherapy group, respectively, after propensity-score matching. The 5-year overall survival (OS) and cancer-specific survival (CSS) were 38.1% and 40.0% for neoadjuvant chemoradiotherapy and 26.3% and 26.5% for adjuvant chemoradiotherapy, respectively [P<0.0001, hazard ratio (HR): 0.7418, 95% confidence interval (CI): 0.6434–0.8553; P<0.0001, HR: 0.7444, 95% CI: 0.6454–0.8587)]. When stratified by stage, stage IIA (P=0.4166, HR: 0.8575, 95% CI: 0.5917–1.243) and IIIA (P=0.0740, HR: 0.7687, 95% CI: 0.5748–1.028) did not show improved 5-year OS in patients receiving neoadjuvant chemoradiotherapy. When stratified by age, similar trends were observed for patients aged more than 75 years. The multivariable analysis showed a significant association of neoadjuvant chemoradiotherapy with better survival. CONCLUSIONS: Neoadjuvant chemoradiotherapy might improve the long-term survival of patients with stage I–IIIA non-small cell lung cancer (NSCLC). For patients aged more than 75 years, neoadjuvant chemoradiotherapy was not associated with an improvement in survival.