Irinotecan Monotherapy Versus Irinotecan-Based Combination as Second-Line Chemotherapy in Advanced Gastric Cancer: A Meta-Analysis

Purpose A meta-analysis was conducted to examine the question of whether combination regimens are more effective than monotherapy as a second-line chemotherapy in advanced gastric cancer. Materials and Methods The MEDLINE and the EMBASE databases and the Cochrane Central Register for Controlled Trials were searched using appropriate keywords. Only randomized controlled trials were eligible. Results Taxane-based study is rare; thus, four irinotecan-based studies were finally included in the meta-analysis. Out of 661 patients, 331 patients were assigned to combination therapy and 330 to monotherapy. Cisplatin or fluoropyrimidine (S-1 or 5-fluorouracil) was used as a combination partner to irinotecan. The pooled hazard ratio (HR) for overall survival (OS) and for progression-free survival (PFS) was 0.938 (95% confidence interval [CI], 0.796 to 1.104; p=0.442) and 0.815 (95% CI, 0.693 to 0.958; p=0.013). In subgroup analysis according to previous exposure to a partner agent, the PFS benefit of combination was observed only in the partially exposed group (HR, 0.784; 95% CI, 0.628 to 0.980; p=0.032). Conclusion Second-line irinotecan-based combination was not associated with increased OS, but with PFS benefit, which seemed particularly significant for patients receiving combination with a new agent.