[A randomized controlled trial to evaluate the effect of adjuvant oral fluoropyrimidine derivative therapy after curative resection for stage II/III rectal cancer-adjuvant chemotherapy trial of S-1 for rectal cancer (ACTS-RC):].

We are conducting a prospective randomized trial to evaluate the survival benefit of adjuvant chemotherapy with S-1 (tegafur, gimeracil, oteracil potassium) and UFT (uracil-tegafur) after curative surgery for patients with Stage II and III rectal cancer. Patients are randomized to either administration of UFT (control) or S-1. UFT was orally administered for 5 days (400 mg/m2/day) followed by two days rest for a year. S-1 was orally administered for 4 weeks (80 mg/m2/day) followed by two weeks rest for a year. The primary endpoint is relapse-free survival (RFS) rate, and the secondary endpoints are overall survival time (OS) and frequency or level of adverse events. We aim to include 400 patients in each of the treatment groups and assume that the registration period will last until 2009.