Effectiveness of carboplatin vs cisplatin in lung cancer chemo-immunotherapy: A systematic review and meta-analysis

Introduction: Chemo-immunotherapy (CT-IT) currently represents the standard therapy for both non-small (NSCLC) and small cell lung cancer (SCLC). However, the differential impact of platinum compounds on immunotherapy outcomes remains to be determined. Methods: A systematic review was conducted to identify randomized controlled trials (RCTs) of combinations of immune check-point inhibitors (ICIs) and platinum-based chemotherapy (CT), providing separate outcome data for carboplatin and cisplatin. Since no direct comparison between the two platinum compounds was reported, a network meta-analysis was performed. The primary endpoints were overall survival (OS) and progression-free survival (PFS) for advanced NSCLC and SCLC and event-free survival (EFS) for early-stage NSCLC. Results: Eleven RCTs including 6125 patients were analyzed. In extensive-stage SCLC (four trials, 2663 patients), a non-significant trend toward improved OS was observed with cisplatin-based regimens (HR: 0.92, 95% CI 0.72–1.18; I2=47%). In advanced NSCLC (four trials, 1948 patients), a non-significant trend toward improved PFS was observed with carboplatin-based regimens (cisplatin vs carboplatin HR: 1.11, 95% CI 0.89–1.39; I2=0%). In early-stage NSCLC (three trials, 1514 patients), no differences emerged in EFS between subgroups (p=0.65 fixed-effect; p=0.49 random-effects). Conclusions: Our analysis does not demonstrate a statistically significant difference between cisplatin- and carboplatin-based CT-IT in lung cancer, although stage- and histology-specific numerical trends were observed. Given the absence of head-to-head comparisons and the lack of disaggregated baseline data, these findings should be considered exploratory.