Benefit of Adjuvant Chemotherapy for Patients Older Than 75 Years With Completely Resected p-Stage II-IIIA Non–Small-Cell Lung Cancer: A Retrospective Cohort Study Using Japanese Nationwide Real-World Data

Abstract

BackgroundThe efficacy of adjuvant chemotherapy (ACT) in elderly patients with completely resected p-stage II-IIIA non–small-cell lung cancer (NSCLC) remains unclear because all previous randomized controlled trials on ACT have been conducted among patients aged <75 years. Thus, this study aimed to evaluate the effectiveness of ACT in elderly patients with completely resected NSCLC. PatientsWe extracted the nationwide data of 812 patients aged ≥75 years who underwent lobectomy with mediastinal nodal dissection in 2010 and were diagnosed with p-stage II-IIIA NSCLC, from nationwide registry data accumulated in 2016. MethodsWe classified the 812 patients into 2 groups based on the ACT administration status and analyzed the differences in their postoperative overall survival (OS). ResultsOverall, 295 patients received ACT (36.3%; group A), whereas 517 patients did not (63.70%; group N). Group A showed significantly better OS as a whole (hazard ratio [HR]: 0.650 [95% confidence interval {CI}: 0.526-0.804]), in the p-stage II subset (HR: 0.688 [95% CI: 0.513-0.925]), and p-stage IIIA subset (HR: 0.547 [95% CI: 0.402-0.743]) than group N. Even after propensity score matching, group A showed significantly better OS as a whole (HR: 0.626 [95% CI: 0.495-0.792]), in the p-stage II subset (HR: 0.690 [95% CI: 0.493-0.964]), and p-stage IIIA subset (HR: 0.554 [95% CI: 0.398-0.772]) than group N. ConclusionACT is recommended even in elderly patients with completely resected p-stage II-IIIA NSCLC. Hence, physicians should not avoid ACT in patients with completely resected NSCLC based solely on age.