A prospective observational study of postoperative adjuvant chemotherapy for non-small cell lung cancer in elderly patients (≥ 75 years)

Background To examine the effects of postoperative adjuvant chemotherapy for elderly ( ≥ 75 years of age) patients with completely resected non-small cell lung cancer (NSCLC), we conducted a multi-institutional and prospective observational study. Methods Patients were recruited between January 2014 and December 2017, and assigned to two cohort groups based on the patients’ choice either to receive postoperative adjuvant chemotherapy (Cohort B) or not (Cohort A). All the patients were observed for 2 years after enrollment. The primary endpoint was the postoperative change of Karnofsky Performance Status (KPS) at 2 years. The secondary endpoints were postoperative recurrence-free survival (RFS) and overall survival (OS) at 2 years, and the completion rate of the adjuvant chemotherapy. Results Two hundred and seventy-two patients were enrolled (Cohort A, n = 225; Cohort B, n = 47). At any time point after surgery, no marked difference of KPS was observed between Cohort B and Cohort A. The RFS at 2 years was 70.8% (95% confidence interval [CI], 64.3–76.4) in Cohort A and 76.0% (95% CI 60.8–85.9) in Cohort B. The OS at 2 years was 85.9% (95% CI 80.4–89.9) in Cohort A and 89.1% (95% CI 75.8–95.3) in Cohort B. The completion rate of planned chemotherapy was 49.9% (95% CI 34.1–63.9%). Conclusions The elderly patients were not likely to choose to receive postoperative adjuvant chemotherapy; however, no significant adverse effect on postoperative KPS was identified. Trial registration Clinical Trial Registration ID: UMIN000020736.