A phase II study of preoperative concurrent chemoradiotherapy with TS-1/ Oxaliplatin in patients with locally advanced rectal cancer(PerSeUS-RC01)

INTERVENTION: Chemoradiaotherapy TS‐1: TS‐1 is administered orally twice daily at a dose of 80‐120 mg/day on Days 1‐5, 8‐12, 22‐26, 29‐33. Oxaliplatin: Oxaliplatin is administered intravenously at a dose of 50 mg/m2 on Days 1, 8, 22, 29. Radiation: 1.8 Gy/day 25 times (total 45 Gy) Chemotherapy Chemotherapy with TS‐1 and oxaliplatin will be performed after chemoradiotherapy. TS‐1: TS‐1 is administered orally twice daily at a dose of 80‐120 mg/day on days 1‐14 every 21 days. Oxaliplatin: Oxaliplatin is administered intravenously at a dose of 130 mg/m2 on Day 1 every 21 days. CONDITION: locally advanced rectal cancer PRIMARY OUTCOME: Pathological effect SECONDARY OUTCOME: Pathological complete response rate; R0 resection rate; Disease free survival; Overall survival; Local recurrence rate; Distant recurrence rate; Safety; Relative Dose Intensity INCLUSION CRITERIA: 1) Main lesion of the tumor is located at the Ra or Rb 2) Histologically confirmed rectum adenocarcinoma (tub1/tub2) 3) Clinical stage T3 or T4 (any N) 4) Possible to R0 resection 5) Without metastases 6) Age of 20 to 80 years 7) An Eastern Cooperative Oncology Group performance status of 0 or 1 8) No prior therapy (radiotherapy, chemotherapy and endocrine therapy) 9) Sufficient organ function as below : 1. WBC: >=3,000/mm3 and <=12,000/mm3 2. Neutrophil: >=1,500/mm3 3. Platelet: >=100,000/mm3 4. Hemoglobin: >=9.0g/dL 5. AST, ALT: <=100IU/L 6. Serum total bilirubin: <=2.0mg/dL 7. Serum creatinine: <=1.2mg.DL 8. Creatinine clearance: >= 60mL/min 10) Adequate oral intakes 11) Written informed concent