Feasibility and safety of platinum-doublet therapy in patients with small-cell lung cancer in the third-line setting: A multi-institutional retrospective study

Small-cell lung cancer (SCLC) is a highly malignant tumor, and no standard third-line therapy has been established. The present study retrospectively analyzed the efficacy and safety of platinum-based regimens in patients with third-line SCLC who received third-line chemotherapy. The association of regimen type with overall survival (OS) or time to treatment failure (TTF) was evaluated using the Cox hazard proportional method, including well-known covariates affecting the prognosis of SCLC. TTF and OS analyses were conducted using the Kaplan-Meier method. The data cutoff date was June 30, 2020. As a result, from January 2015 to August 2019, 111 patients were diagnosed with SCLC, and 37 received third-line chemotherapy. Subsequently, 15 patients received a platinum-doublet regimen, and 22 patients received a single-agent regimen. Only the type of regimen was significantly associated with TTF in univariate analysis (odds ratio, 0.44; 95% confidence interval, 0.20-0.95; P=0.03). There were no significant factors associated with OS. The median TTF of patients receiving a platinum-doublet regimen and those receiving a single-agent regimen were 3.9 and 2.3 months, respectively (P=0.03). The overall response rates of the platinum-doublet and single-agent regimens were 20.0 and 4.5%, respectively. Similarly, the disease control rates were 73.3 and 36.4% for platinum-doublet and single-agent regimens, respectively. There was a tendency for adverse events (AEs) with any grade to occur more often in platinum-based regimens compared with in single-agent regimens. Severe AEs of grade 3 or higher were observed more often in the platinum-based regimen, especially in myelosuppression. In conclusion, the present study demonstrated the feasibility and safety of platinum-doublet regimens in patients with SCLC in a third-line setting (Registration no. 2020-048. Date of registration, June 5, 2020).