The efficacy of amrubicin third‐line chemotherapy in patients with relapsed extensive‐disease small‐cell lung cancer: A retrospective and historical study in a single institute

BACKGROUND: The efficacy of amrubicin for relapsed small‐cell lung cancer (SCLC) has been reported in previous studies. Few reports, however, describe the efficacy and survival benefit of third‐line amrubicin chemotherapy in patients with extensive disease (ED)‐SCLC. METHODS: We retrospectively analyzed the clinical records of ED‐SCLC patients treated with amrubicin salvage chemotherapy as a third‐line chemotherapy between January 2005 and July 2016 (salvage amrubicin group). The efficacy and toxicities of amrubicin were evaluated. Overall survival (OS) in the amrubicin salvage group was compared with OS among ED‐SCLC patients treated with at least second‐line chemotherapy between May 2000 and July 2016 and without subsequent amrubicin salvage chemotherapy. RESULTS: A total of 18 patients with a median age of 70 years were analyzed in the amrubicin salvage group. The median number of treatment cycles of amrubicin was four. The response rate was 27.8% (95% confidence interval (CI), 7.1%–48.5%), and the disease control rate (DCR) was 66.7% (95% CI, 44.9%–88.4%). Median progression‐free survival was 2.9 months (95% CI, 1.0–4.9 months), and median OS after an initial chemotherapy was 18.1 months (95% CI, 10.2–26.0 months). OS in the amrubicin salvage group was significantly longer than in the no‐amrubicin group (n = 19; 12.6 months, 95% CI, 11.5–13.8 months, P = 0.005). The frequency of neutropenia greater than grade 3 was 72.2%, with febrile neutropenia developing in 38.9% of patients in the amrubicin salvage group. CONCLUSIONS: Despite a high frequency of febrile neutropenia, amrubicin salvage chemotherapy may improve OS in patients with relapsed ED‐SCLC.