Phase II trial of combined treatment consisting of preoperative S-1 plus cisplatin followed by gastrectomy and postoperative S-1 for stage IV gastric cancer

Background To improve the poor prognosis in patients with stage IV (StIV) gastric cancer (GC), we conducted a multicenter phase II study of preoperative S-1 plus cisplatin followed by gastrectomy and postoperative S-1 for StIV GC (the protocol is registered at the clinical trial site of the National Cancer Institute; KYUH-UHA-GC03-01, NCT00088816). Methods Eligibility criteria included histologically proven StIVGC. Patients received S-1 (80 mg/m2/day, days 1–21) plus cisplatin (60 mg/m2 on day 8) for 2 courses. After preoperative chemotherapy (CTx), radical gastrectomy was performed. Postoperative S-1 (80 mg/m2/day, days 1–14) was administered every 3 weeks for 1 year. Results Fifty-one patients were enrolled and all patients were followed for more than 2 years. The 2-year overall survival and progression-free survival rates were 43.1% (95% confidence interval [CI] 29.4–56.1%) and 33.3% (95% CI 20.9–46.2%), respectively. Preoperative chemotherapy was accomplished in 44 patients (86.3%). These 44 patients underwent surgery and R0 resection was achieved in 26. The rate of R0 resection for GC with a single StIV factor (n = 24) was 79.2% and that for GC with multiple StIV factors (n = 27) was 25.9%. All patients with cancer cells in peritoneal washings (cytology [Cy] 1) alone (n = 12) became Cy0 after preoperative chemotherapy. Postoperative chemotherapy was completed in 11 patients, including 8 with Cy1 alone. No treatment-related death was recorded. Recurrences were observed in 14 patients after R0 resection. The most frequent recurrence site was the peritoneum. Patients who underwent R0 resection and those with Cy1 alone had a better survival. Conclusions This perioperative treatment was safe and feasible for StIVGC but failed to show a survival benefit. In patients with StIVGC with Cy1 alone this treatment resulted in a better prognosis.