Gemcitabine and S-1 versus gemcitabine and cisplatin treatment in patients with advanced biliary tract cancer: a multicenter retrospective study.

Objective This study aimed to compare the safety and efficacy of the combination therapy of gemcitabine and S-1 (GS) versus gemcitabine and cisplatin (GC) in patients with advanced biliary tract cancer (BTC). Methods In this multicenter retrospective cohort study, a total of 212 patients with advanced BTC receiving GS (n = 125) or GC (n = 87) between July 2006 and August 2015 were analyzed. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective tumor response, and safety. Results Patient characteristics were well balanced between the two groups, except for tumor size (the baseline sum of the largest diameter of the tumor: 6.3 cm in the GS group vs. 8.6 cm in the GC group, p = 0.01). Although the response rate was higher in the GS group than in the GC group (28.8% vs. 10.3%, p = 0.01), the median PFS and OS were comparable between the two groups (PFS of 5.6 vs. 7.6 months, p = 0.74; OS of 12.4 vs. 9.2 months, p = 0.20, respectively). Stomatitis and skin rash were more frequently observed in the GS group, whereas anemia, thrombocytopenia, nausea, and renal toxicity were more commonly observed in the GC group. Conclusion This study demonstrates that GS and GC are similar with regard to their safety and efficacy in patients with advanced BTC. GS could serve as an alternative treatment for advanced BTC as a first-line chemotherapy.