Survival and prognostic factors in elderly patients receiving second-line chemotherapy for relapsed small-cell lung cancer: Results from the Japanese Joint Committee of Lung Cancer Registry

•Second-line chemotherapy represented substantial overall survival time in elderly patients with relapsed SCLC in the nationwide registry database.•OS is significantly prolonged in patients with good performance status.•OS is significantly prolonged in patients with a long interval from the start of first-line therapy to that of second-line therapy. Most patients with small-cell lung cancer (SCLC) experience relapse because of the emergence of drug-resistant tumor cells. Therefore, second-line therapy is subsequently required to prolong their survival. However, it is unclear whether second-line chemotherapy can provide a survival benefit to elderly patients with relapsed SCLC. Therefore, this study aimed to evaluate survival and identify prognostic factors in an elderly population. Based on a nationwide registry database of patients with SCLC (the Japanese Joint Committee of Lung Cancer Registry), we retrospectively reviewed medical records of patients aged ≥ 75 years with relapsed SCLC who subsequently received second-line chemotherapy. Survival time since the initiation of second-line chemotherapy was evaluated. Among 731 patients aged ≥ 75 years with SCLC who were accumulated by the nationwide registry database, this study included 228 patients, comprising 190 men and 38 women with a median age of 78 years. The number of patients with performance status (PS) of 0−1 and 2−4 was 196 and 32, respectively. The overall survival (OS) and 1-year survival rates were 7.5 months and 24 %, respectively. A multivariate analysis identified PS, clinical stage at the time of starting first-line therapy, and the interval from the start of first-line therapy to that of second-line therapy as independent prognostic factors. This study with the nationwide registry database showed that among the relapsed elderly SCLC patients who received second-line chemotherapy, a substantial OS may be expected in patients with good PS, at an early clinical stage at the time of starting first-line therapy, and with a longer interval from the start of first-line therapy to that of second-line chemotherapy.