Randomized phase II study of dose schedule of TS-1 for resected Colorectal Cancer

Interventions: Standard Arm(Daily administrations) TS-1 is administered orally for 28 days, followed by 14 days rest. Administrations are conducted for 24 weeks from the date of the start of the therapy. After the treatment, patients are simply observed without any more therapy, unless any recurrent lesions or any other cancer lesions are observed in them. Testing Arm(Alternate-day administrations) TS-1 is administered orally at Monday, Wednesday, Friday and Sunday. Administrations are conducted for 28 weeks from the date of the start of the therapy. After the treatment, patients are simply observed without any more therapy, unless any recurrent lesions or any other cancer lesions are observed in them. Primary outcome(s): Treatment Completion Rate Study Design: Parallel Randomized