Study: NCT01333709

Intervention type: DRUG
Group type: OTHER
Intervention: Induction trichemotherapy - FOLFIRINOX regimen
Description: A short (4 cycles) and intensive trichemotherapy combinig irinotecan 180 mg/m2, oxaliplatin 85 mg/m2, elvorin 200 mg/m2, 5-Fu (bolus 400 mg/m2, followed by a 46-hour continuous infusion 2,400 mg/m2) will be delivered for 8 weeks (D1=D15).

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Induction trichemotherapy - FOLFIRINOX regimen
Description: A short (4 cycles) and intensive trichemotherapy combinig irinotecan 180 mg/m2, oxaliplatin 85 mg/m2, elvorin 200 mg/m2, 5-Fu (bolus 400 mg/m2, followed by a 46-hour continuous infusion 2,400 mg/m2) will be delivered for 8 weeks (D1=D15).

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Early tumor response evaluation by MRI volumetry
Description: Two weeks after the CT completion, the tumor volume will be measured by MRI with specific software which automatically borders the tumor so as to determine the early tumor response. A centralized reassessment of all MRI exams will be systematically performed by two radiologists of the coordinator center.

Intervention type: OTHER
Group type: OTHER
Intervention: Early tumor response evaluation by MRI volumetry
Description: Two weeks after the CT completion, the tumor volume will be measured by MRI with specific software which automatically borders the tumor so as to determine the early tumor response. A centralized reassessment of all MRI exams will be systematically performed by two radiologists of the coordinator center.

Intervention type: OTHER
Group type: OTHER
Intervention: Early tumor response evaluation by MRI volumetry
Description: Two weeks after the CT completion, the tumor volume will be measured by MRI with specific software which automatically borders the tumor so as to determine the early tumor response. A centralized reassessment of all MRI exams will be systematically performed by two radiologists of the coordinator center.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Early tumor response evaluation by MRI volumetry
Description: Two weeks after the CT completion, the tumor volume will be measured by MRI with specific software which automatically borders the tumor so as to determine the early tumor response. A centralized reassessment of all MRI exams will be systematically performed by two radiologists of the coordinator center.

Intervention type: RADIATION
Group type: OTHER
Intervention: Radiochemotherapy Cap 50
Description: RCT Cap 50 will combine radiotherapy at a dose of 50 Gy by either conventional 3D or IMRT (2 Gy per fraction, 5 fractions per week during 5 weeks / 44 Gy in mini pelvis, and boost 6 Gy on reduced peritumoral volume) with concomitant oral capecitabine at 1600 mg/m2 per day delivered the days of RT treatment (2 daily intake).

Intervention type: RADIATION
Group type: OTHER
Intervention: Radiochemotherapy Cap 50
Description: RCT Cap 50 will combine radiotherapy at a dose of 50 Gy by either conventional 3D or IMRT (2 Gy per fraction, 5 fractions per week during 5 weeks / 44 Gy in mini pelvis, and boost 6 Gy on reduced peritumoral volume) with concomitant oral capecitabine at 1600 mg/m2 per day delivered the days of RT treatment (2 daily intake).

Intervention type: RADIATION
Group type: EXPERIMENTAL
Intervention: Radiochemotherapy Cap 60
Description: RCT Cap 60 will combine radiotherapy at a dose of 60 Gy by either conventional 3D or IMRT (2 Gy per fraction, 5 fractions per week during 6 weeks / 44 Gy in mini pelvis, and boost 16 Gy on reduced peritumoral volume) with concomitant oral capecitabine at 1600 mg/m2 per day delivered the days of RT treatment (2 daily intake)

Intervention type: PROCEDURE
Group type: EXPERIMENTAL
Intervention: Radical proctectomy with total mesorectal excision
Description: The proctectomy can be performed by laparoscopic surgery or conventional laparotomy.

Intervention type: PROCEDURE
Group type: OTHER
Intervention: Radical proctectomy with total mesorectal excision
Description: The proctectomy can be performed by laparoscopic surgery or conventional laparotomy.