Platinum-doublet chemotherapy as second-line treatment for relapsed patients with small-cell lung cancer: A systematic review and meta-analysis

Objective: Optimal second-line chemotherapy for patients with relapsed small-cell lung cancer remains debatable. In addition to topotecan or amrubicin monotherapy, re-challenge with first-line platinum-doublets have been commonly used. In this study, we investigated whether platinum-doublets are suitable as second-line treatment for relapsed small-cell lung cancer. Materials and methods: Studies that enrolled relapsed small-cell lung cancer and compared platinum-doublets with non-platinum-based regimens for second-line treatment were identified using PubMed and EMBASE. A meta-analysis was conducted to calculate the relative risk of objective response rate and disease control rate of the second-line chemotherapy. Subgroup analyses were conducted to focus on comparison with standard second-line regimens and sensitive relapse. Progression-free and overall survival, and adverse events were systematically reviewed. Results: Ten studies published between 2011 and 2020 were included in our analysis with a total of 1222 patients: 438 treated with platinum-doublets and 784 with non-platinum-based regimens. The objective response rates for second-line platinum-doublet and non-platinum regimens were 47.3 % [95 % CI: 40.5–54.0] and 31.5 % [95 % CI: 22.2–40.8], respectively. Patients treated with platinum-doublets had a significantly higher objective response rate than patients with non-platinum-based regimens (RR [95 % CI]: 1.527 [1.100–2.121], p = 0.011), as well as disease control rate (RR [95 % CI]: 1.152 [1.052–1.262], p = 0.002). In a subgroup analysis comparing platinum-doublets with topotecan or amrubicin, patients treated with platinum-doublets had significantly higher objective response rate and disease control rate (RR [95 % CI]: 1.663 [1.055–2.619], p = 0.028 and 1.170 [1.021–1.340], p = 0.023 respectively). Progression-free and overall survival appeared consistent with the tumor responses. Adverse events associated with platinum-doublets appeared acceptable compared with the monotherapies. Conclusion: Platinum-doublet chemotherapy as second-line treatment for patients with relapsed small-cell lung cancer can be considered as a reasonable option in comparison with non-platinum regimens.