mFOLFIRINOX
DrugInvestigational arm: Neoadjuvant chemotherapy mFolfirinox, 4 cycles: oxaliplatin: 85 mg/m² in 2 hours at D1 irinotecan: 180 mg/m² in 90 min at D1 folinic acid: 400 mg/m² simultaneously in 2 hours at D1 during the irinotecan infusion 5-FU: 2400 mg/m² continuous infusion during 48 hours (1200 mg/m² at D1 and D2), every 14 days during 2 months (4 cycles), then CRT (50 Gy (2 Gy/session, 25 fractions) + capecitabine 800 mg/m² twice a day 5 days/7), then surgery with TME 6-8 weeks after chemoradiation, and 4 months of adjuvant CT depending on the center's choice.