A phase II trial of oxaliplatin plus S-1 as a first-line chemotherapy for patients with advanced gastric cancer

Abstract

Background Palliative chemotherapy has been shown to have a survival benefit for patients with recurrent or metastatic gastric cancer. We conducted a Phase II trial to determine the efficacy and safety of S-1 plus oxaliplatin (SOX regimen) as first-line chemotherapy for patients with unresectable locally advanced or metastatic gastric cancer. Methods Eligible patients had measurable lesions and no previous history of chemotherapy (except adjuvant chemotherapy). Oxaliplatin was administered intravenously at a dose of 130 mg/m2 on day 1. S-1 was administered orally in doses of 80, 100, or 120 mg/d according to body surface areas of <1.25 m2, 1.25–1.5 m2, or >1.5 m2 respectively; the total dose was divided into two daily doses on days 1–14. Treatments were repeated every 3 weeks until disease progression or intolerable toxicity occurred. Results Forty-three patients were enrolled in the study. All were assessable for efficacy and adverse events. The objective response and disease control rates were 55.8% and 76.7% respectively. The median follow-up time was 16.5 months. The median progression-free survival time was 7 months (95% CI, 5.8–8.2 months) and the median overall survival time was 16.5 months (95% CI, 9.7–23.3 months). The one-year survival rate was 54.2%. Major adverse reactions were grade 3/4 neutropenia (9.3%) and thrombocytopenia (20.9%). Conclusion The SOX regimen with oxaliplatin at a dose of 130 mg/m2 was found to be effective and safe as a first-line chemotherapy in Chinese patients with advanced gastric cancer.