Multicenter Phase 2 Trial: a Tailored Strategy for Locally Advanced Rectal Carcinoma

Inclusion Criteria:

* Histologically confirmed rectal carcinoma
* Primary tumor evaluated by pelvic MR Imaging:

  i) iT3 ≥c tumors, with MRI showing a predictive CRM ≤ 2 mm or a EMS (Extra Mural Spread) ≥ 5 mm

ii) Resectable iT4 tumors (only randomized within the "poor responders" group)

iii) Any T tumors with MRI showing a predictive CRM ≤ 1 mm

* No detectable metastases: Thorax-abdomen-pelvic CT-scan
* Patient ≥ 18 years
* ECOG Performance Status 0-1-2
* Patient information and written informed consent form signed
* Patient who can receive radiotherapy and chemotherapy
* Negative pregnancy test in women of childbearing potential
* Patient covered by a Social Security system
* Hematology : Haemoglobin ≥ 9 g/dL, WBC ≥ 4000/mm3, neutrophils ≥ 1.5 x 109/L, platelets ≥ 100 x 109/L
* Hepatic function : total bilirubin ≤ 1.5 x ULN, AST and ALT ≤ 3 x ULN, Alkaline phosphatases ≤ 3 x ULN
* Renal function : creatinine ≤ 1.25 x ULN or creatinine clearance ≥ 60 ml/min

Exclusion Criteria:

* Indication for immediate surgery
* Primary tumor not measured at the MRI before inclusion
* Previous pelvic radiotherapy
* Contraindication to radiotherapy and/or chemotherapy
* Severe renal or liver impairment
* Cardiac and/or coronary disease which could contraindicate 5-Fu administration
* Active infectious disease
* Peripheral sensitive neuropathy
* History of prior cancer (except if it was cured more than 5 years ago, and if complete remission)
* Patient (male or female) of reproductive potential not using an effective contraceptive method during the whole treatment and up to 6 months after the completion of treatment
* Concurrent participation in any other clinical trial likely to interfere with the therapeutic schedule
* Fertile female patient not using adequate contraception, or breast-feeding woman