Randomized phase II study comparing paclitaxel with S-1 vs. S-1 as first-line treatment in patients with advanced gastric cancer

This randomized phase II study was conducted to compare the efficacy and safety of paclitaxel with S-1 (PS) vs. S-1 in patients with advanced gastric cancer (AGC). Eighty-two (82) patients were 1:1 randomly assigned to oral S-1 (daily for 2 weeks, every 4 weeks' cycle) or S-1 (daily for 2 weeks, every 4 weeks' cycle) plus paclitaxel (on day 1, 8 and 15 of a 4 weeks' cycle). S-1 was orally administered with a fixed quantity according to body surface area (BSA), while paclitaxel was given 60 mg/m(2) i.v. daily through an implanted catheter. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), overall responsible rates and safety. The median OS with PS versus S-1 monotherapy was 14.0 versus 11.0 months (P = 0.02), survival at 12 months was 61.0 % in the PS group and 46.3 % in the S-1 group. Median PFS was also significantly longer in the PS group (6.0 months) than in the S-1 group (4.0 months). The overall response rate was determined in 82 evaluable patients, and was significantly higher (P = 0.04) with PS (19 patients, 46.3 %) than with S-1 monotherapy (10 patients, 24.4 %). PS was well tolerated with no treatment-related deaths, all were grade 3-4 gastrointestinal toxicities, including anorexia, nausea, and diarrhea developed in less than 10 % of the patients. Combination chemotherapy of paclitaxel with S-1 is well tolerated and active in AGC patients. Further investigation with comparative trials is needed for confirmation.