Non Inferiority Study of Preoperative Chemotherapy Without Pelvic Irradiation for Rectal Cancer

"Arm A : Experimental~* Intervention Type : Drug~* Intervention Name : Modified FOLFIRINOX (experimental arm)~* Intervention Description : preoperative chemotherapy: Modified FOLFIRINOX regimen comprised oxaliplatin 85mg/m2 + irinotecan 180mg/m2 + Folinic acid 400 mg/m2 at day1, then 5-FU given as a continuous infusion over 46h every two weeks. Six cycles are planned preoperatively."

"Arm B: Active comparator~* Intervention Name : modified FOLFIRINOX followed by preoperative standardized radiochemotherapy (control arm)~* Intervention Description : preoperative chemotherapy: Modified FOLFIRINOX regimen comprised oxaliplatin 85mg/m2 + irinotecan 180mg/m2 + Folinic acid 400 mg/m2 at day1, then 5-FU given as a continuous infusion over 46h every two weeks. Six cycles are planned preoperatively.followed by preoperative radiochemotherapy with concurrent capecitabine 825 mg/m2/12h 5 days/week and intensity modulated radiation therapy using a simultaneous integrated boost technique with 45 Gy in 25 fractions in pelvic volume and 50 Gy in 25 fractions to the tumor."