Phase II multi-institutional prospective randomized trial comparing S-1 plus paclitaxel with paclitaxel alone as...

The aim of this study was to explore whether a combination of S-1 and paclitaxel offers any benefit over paclitaxel alone to patients pretreated by S-1.

Gastric cancer patients who developed progression during S-1-based first-line chemotherapy or had recurrence during postoperative adjuvant chemotherapy by S-1 were randomly assigned to receive second-line treatment either by weekly administration of paclitaxel at 80 mg/m(2) three times every 4 weeks or daily oral S-1 (80 mg/m(2)) for 2 weeks plus paclitaxel (50 mg/m(2)) given on days 1 and 8, every 3 weeks (S-1 plus paclitaxel). The primary endpoint was progression-free survival (PFS) at 4 months after the initiation of treatment.

A total of 78 patients were eligible for efficacy analyses-40 were assigned to the paclitaxel group and 38 to the S-1 plus paclitaxel group. PFS at 4 months was similar between the groups (50 % for paclitaxel vs 55 % for S-1 plus paclitaxel, P = 0.641). There were no differences between the groups either in progression-free survival (4.6 vs 4.6 months, respectively, P = 0.526), overall survival (10.0 vs 10.0 months, respectively, P = 0.464), or overall response rate (27 vs 22 %, respectively, P = 0.767). The incidences of grade 3 or 4 hematological and non-hematological toxicities were also equivalent between the two groups (25 vs 26 % and 24 vs 26 %, respectively).

No benefit of S-1 administration beyond progression was shown when paclitaxel was selected as the key drug for second-line chemotherapy.