Comparison of Efficacy and Safety of Second-Line Treatment Options for Advanced Small-Cell Lung Cancer: A Retrospective Analysis

Objective: As monotherapy such as topotecan has reached a plateau of effectiveness, new second-line treatments based on experience have been used in clinical application. This study compared the efficacy and safety of different second-line treatments for advanced small-cell lung cancer (SCLC).Methods: A total of 380 patients with advanced SCLC were screened selectively in the retrospective study. Adverse events and patient responses were assessed using Common Terminology Criteria for Adverse Events v5.0 and Response Evaluation Criteria for Solid Tumors v1.1. The progression-free survival (PFS) was estimated using the Kaplan-Meier method or Cox survival regression model and compared using the log-rank test.Results: In the platinum-resistant group, disease control rate (DCR) and median PFS (mPFS) were prolonged in the combination group versus single-agent group (DCR: 49.24% vs 24.39%, P = .004; mPFS: 3.73 vs 1.90 months, P < .001). Grade 3/4 toxicity was similar between the 2 groups (P = .683). The mPFS did not differ among single-agent groups (P = .380). No significant difference was observed in mPFS of different combination therapy groups (P = .170). In terms of platinum-based chemotherapy, the DCR and mPFS were prolonged in irinotecan-platinum group versus taxol-platinum group (DCR: 56.14% vs 9.09%, P = .004; mPFS: 3.87 vs 1.93 months, P = .012). Grade 3/4 toxicity was similar between the 2 groups (P = .614). The mPFS was prolonged in the chemotherapy plus immunotherapy group versus single-agent chemotherapy group (P = .003). In the platinum-sensitive group, the mPFS did not differ between the combination group and single-agent group (P = .200). The mPFS did not differ among different single-agent groups (P = .260) or combination groups (P = .150). There was no difference in mPFS among different platinum-based chemotherapy groups (P = .830).Conclusions: For patients with platinum-resistant SCLC, combination therapy has shown better efficacy and acceptable toxicity profile than monotherapy. Among combination therapies, irinotecan-platinum has shown better efficacy than taxol-platinum. For patients with platinum-sensitive SCLC, the efficacy of different single-agent or combination therapies was similar.