Phase I study of neoadjuvant chemoradiotherapy consisting of S-1 and cisplatin for patients with resectable advanced gastric cancer (KOGC-01).

Background: The prognosis for advanced gastric cancer is poor, with surgery as the only treatment for resectable advanced gastric cancer. Therefore, treatment options that might improve the prognosis are needed. To that end, neoadjuvant chemoradiotherapy with S-1 and cisplatin (CDDP) was investigated.

Patients And Methods: The chemotherapy schedule included one cycle repeated after 6 weeks. S-1 was administered orally every day on days 1-21 and CDDP was infused on days 1, 8 and 15. Radiation therapy was started concurrently with chemotherapy and repeated daily on days 1-5, 8-12, 15-19, and 22-26.

Results: A total of 10 patients were recruited. The first four patients were entered into level 1 (CDDP, 20 mg/m²). The next six patients were entered into level 0 (15 mg/m²), because of dose-limiting toxicity (delaying the second course of chemotherapy in two patients) that had been observed at level 1. The maximum tolerated dose (MTD) of CDDP was 20 mg/m². Seven patients underwent surgery and all had an R0 (no residual tumor) resection without surgical complications.

Conclusion: Neoadjuvant chemoradiotherapy with S-1 and CDDP may cause surgery to be delayed, but shows promise for resectable advanced gastric cancer.