Comparison of efficacy of S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (XELOX) in patients with recurrent or metastatic gastric cancer

Abstract

Purpose: This randomized phase II trial evaluated two oxaliplatin-based regimens (SOX or XELOX) as first-line treatment of advanced gastric cancer with the aim to select a regimen for future phase III trial.

Methods: Patients with recurrent or metastatic gastric cancer , a performance status ≤ 2, and adequate organ functions were randomly received oxaliplatin (130mg/m2) on day 1 plus S-1 (80 mg/m2/day) from day 1 to day 14 (SOX), or the same dose of oxaliplatin plus capecitabine (2000 mg/m2day) from day 1 to day 14 (XELOX). The schedules were repeated every 3 weeks. Study endpoints included survival, response rate, toxicity, and quality of life (QOL).

Results: One hundred thirty patients were enrolled; one patients withdrew consent, therefore, 65 patients were assigned to SOX and 65 patients assigned to XELOX. Median time to progression (TTP) was 6.2 months (95% CI, 5.5-6.8 months) with SOX and 7.4 months (95% CI, 5.9-8.9 months) with XELOX. At a median follow-up of 12.4 months, the median OS was 12.4 and 14.1 months with SOX and XELOX, respectively. Median number of cycles administered was 6 (range, 1-31) for SOX, and 7 (range, 1-22) for XELOX and median dose intensity was comparable in both arms. The overall response rates (ORR) were 41% and 44% with SOX and XELOX, respectively. The treatment was generally well tolerated, and the incidence of grade 3 to 4 toxicities was relatively low in the two treatment arm. The most common grade 3/4 toxicity was thrombocytopenia in SOX and neutropenia in XELOX. All grade hand foot syndrome (23%) was more common in XELOX, while grade 3/4 anemia (13%) was more common in SOX.

Conclusions: Both SOX and XELOX regimen were well-tolerated and effective as the first line treatment with metastatic or recurrent gastric cancer.