Randomized phase III trial comparing adjuvant S-1 to capecitabine in stage III colorectal cancer (JCOG0910, CRC Adj-CAPS)

INTERVENTION: A: capecitabine. Patients in this group receive 8 courses of oral capecitabine, at a dose of 1,250 mg/m2 twice daily for 14 days every 21 days. B: S‐1. Patients in this group receive 4 courses of oral S‐1, at a dose of 40 mg/m2 twice daily for28 days every 42 days. CONDITION: Stage III colorectal cancer PRIMARY OUTCOME: Disease‐free survival SECONDARY OUTCOME: Overall survival, Relapse‐free survival, Adverse events (including treatment related death, early death, grade 4 non‐hematological toxicities, grade 2 or more Hand‐foot skin reaction). INCLUSION CRITERIA: 1) Pathologically proven colorectal adenocarcinoma. 2) Tumor is mainly located in between cecum and upper rectum, excluding appendix and that invades to lower rectum. 3) Tumor resection with D2 or D3 lymph node dissection was performed. 4) R0 resection was performed. 5) Stage III cancer by General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus (same as UICC TNM classification 7th ed.). 6) No synchronous colorectal cancer which invade muscularis propria or deeper. 7) Age at registration is of 20 to 80 years old. 8) ECOG Performance status is 0 or 1. 9) No prior chemotherapy or radiation therapy. 10) It is possible to take foods and drugs orally. 11) Within 8 weeks after surgery. 12) Major organ function is preserved.WBC>=3,000/mcl, PLT>=75,000/mcl, GOT<=100 IU/L, GPT<=100 IU/L , Cr<=1.5 mg/dl 13) Witten informed consent is taken