Background: The effect of second-line chemotherapy in patients with non-small cell lung cancer (NSCLC) who received first-line chemotherapy at the age of ≥ 75 years is unclear. Methods: Sixty-five elderly patients with NSCLC who received first-line chemotherapy at the age of ≥ 75 years and treated with second-line chemotherapy at Shizuoka Cancer Center between January 2005 and December 2014 were retrospectively reviewed. Results: The overall response rate of the second-line chemotherapy was 9.2% [95% confidence interval (CI) 4-19]. The median progression-free survival at the second-line chemotherapy was 2.2 months. The median overall survival at the second-line chemotherapy was 7.5 months. Multivariate analysis of prognostic factors showed that an Eastern Cooperative Oncology Group performance-status score (PS 0–1/PS 2; HR, 0.396; 95% CI, 0.192–0.899; p=0.03) and histology (squamous/non-squamous; HR, 0.465; 95% CI, 0.228–0.884; p=0.02) were significantly independent prognostic factors. On the other hand, the number of treatment-related deaths was 2 (3.1%) due to pneumonitis. Moreover, the proportion of patients who received third-line chemotherapy was only 35.9%. Conclusion: Our study suggests that elderly patients have difficulty moving on to the next line of chemotherapy; however, selected elderly patients well tolerated the adverse effects of second-line chemotherapy, and second-line chemotherapy might be effective for elderly patients with NSCLC who received first-line chemotherapy at the age of ≥ 75 years. Therefore, prospective study should be planned in order to demonstrate the efficacy of second-line chemotherapy for elderly patients with NSCLC.
