Irinotecan-Based Regimen as Second-Line Chemotherapy for Extensive- Stage Small Cell Lung Cancer

Purpose: This study evaluates the clinical outcomes of extensive-stage small-cell lung cancer (SCLC) patients who received Irinotecan-based second-line chemotherapy after platinum-based first-line therapy, especially focused on efficacy and toxicity between single-agent and doublet chemotherapy. Patients and methods: We retrospectively reviewed 83 patients who given irinotecan-based second-line chemotherapy for extensive-stage SCLC. Survival curves were plotted using the Kaplan–Meier method. The Cox proportional hazard model was used for multivariate analysis. Results: Fifty-nine patients received doublet chemotherapy and 24 with single-agent treatment. The objective response rate (ORR) was 23.7% in the doublet group and 25% in the single-agent group (P=0.90). The disease control rate (DCR) was 65.7% and 58.3%, respectively, (P=0.71). The Progression-free survival (PFS) was 3.10 months in the doublet group and 2.10 months in the single-agent group (P=0.35). In the sensitive recurrence group, 27 patients were with doublet chemotherapy and 10 with single-agent treatment. The Median PFS was 4.73 months (95% CI: 4.37-5.09) and 3.83months (95% CI: 2.65-5.02), respectively (P=0.543). In the refractory recurrence group, there were 32 patients with doublet chemotherapy and 14 with single-agent treatment. The median PFS was 2.57 months (95% CI: 2.19-2.93) and 1.40 months (95% CI: 1.13-1.64), respectively (P=0.048). The grade III/IV toxicity in single-agent group is lower than doublet group (45.8% vs.71.2%, P=0.029). No difference was found in cancerrelated symptoms improvement between the doublet and single group (P=0.36). Conclusion: Patients with extensive-stage SCLC could benefit from irinotecan-based second-line treatments. The refractory recurrence patients with doublet treatment obtain a moderate PFS advantage than single-agent chemotherapy.