INTRODUCTION: Superiority of camptothecin regimens over etoposide-both combined with platinum analogs-in extensive disease small cell lung cancer has been a matter of debate with contradictory findings in randomized trials. A systematic review was sought to elucidate this issue. METHODS: Randomized controlled trials comparing first-line camptothecin-platinum doublets versus etoposide-platinum doublets in patients with extensive disease small cell lung cancer were searched in MEDLINE, EMBASE, LILACS, and CENTRAL databases, European Society of Medical Oncology, American Society of Clinical Oncology, and International Association for the Study of Lung Cancer meeting sites. Meta-analyses were performed using fixed-effects model. Subgroup analyses were undertaken comparing each type of camptothecin to etoposide-based regimens. The outcomes of interest were overall survival (OS), progression-free survival (PFS), response rate (RR), and toxicities. RESULTS: Eight studies (3086 patients) were included. The meta-analysis of topotecan regimens (TP) was not reliable due to impending heterogeneity. Meta-analysis of trials testing irinotecan combinations (IP) versus etoposide regimens (EP; 1561 patients) stated an OS improvement in favor of IP arm, though with considerable heterogeneity, whose origin seemed to be a Japanese trial. In the analyses without that study (1407 patients left), IP brought a significant improvement in OS (hazard ratio = 0.87; 95% confidence interval 0.78-0.97; p = 0.02; I = 0). IP also increased PFS (hazard ratio = 0.83; 95% confidence interval 0.73-0.95; p = 0.006; I = 0%). There was no impact in RR (absolute RR 56% with IP; 53% with EP; p = 0.17). IP caused more diarrhea (p < 0.0001) but less hematological toxicities (p < 0.001) than EP. CONCLUSIONS: The present meta-analysis demonstrates statistically significant OS and PFS benefits of IP over EP regimens in western and eastern patients. Specific characteristics of safety profile should be taken into account when administrating IP chemotherapy.