Gemcitabine plus S-1: a hopeful frontline treatment for Asian patients with unresectable advanced pancreatic cancer.

Abstract

Gemcitabine-based chemotherapy is widely used for unresectable advanced pancreatic cancer which contains locally advanced and metastatic pancreatic cancer. We performed meta-analysis to examine whether gemcitabine plus S-1 could improve treatment efficacy as first-line chemotherapy for those patients when compared with gemcitabine alone. STATA was used to estimate the summary hazard ratios or odds ratios and their 95% confidence intervals. Heterogeneity among trials was examined by Cochran's χ(2) test. Publication bias was evaluated by Begg's and Egger's tests. Subgroup analysis based on the extent of disease was performed. Four randomized controlled trials including 878 Asian patients were analyzed. In total meta-analysis, gemcitabine plus S-1 significantly improved overall survival (hazard ratio, 0.82; 95% confidence interval, 0.70-0.96; P = 0.015), progression-free survival (hazard ratio, 0.64; 95% confidence interval, 0.55-0.74; P < 0.001), overall response rate (odds ratio, 3.00; 95% confidence interval, 2.04-4.41; P < 0.001) and disease control rate (odds ratio, 1.78; 95% confidence interval, 1.32 to 2.39; P < 0.001), and was associated with more but manageable hematologic (leukocytopenia, neutropenia, thrombocytopenia) and non-hematologic (diarrhea, stomatitis, nausea, rash) adverse events. In subgroup analysis, gemcitabine plus S-1, comparing with gemcitabine, significantly improved overall survival in locally advanced patients (hazard ratio, 0.69; 95% confidence interval, 0.48 to 0.99; P = 0.022) but not in metastatic patients (hazard ratio, 0.75; 95% confidence interval, 0.46-1.23; P = 0.256). This meta-analysis confirmed the survival benefits of gemcitabine plus S-1 as first-line treatment for unresectable advanced pancreatic cancer at least in Asia, while good Eastern Cooperative Oncology group performance status was warranted. Importantly, we highlighted the significant overall survival benefit of gemcitabine plus S-1 in locally advanced patients but not in metastatic patients.