• Written consent,

• Patient who receive Folfirinox,

• Patient aged over 18 years old,

• World Health Organization (WHO) performance status ≥ 1,

• Histologically confirmed diagnosis of adenocarcinoma of the rectum,

• Distal part of the tumor from 1 to 12 cm from the upper part of the levator ani (dynamic rectal examination),

• No unequivocal evidence on CT-Scan of established metastatic disease,

• MRI evaluation of the locally advanced tumor before neoadjuvant chemotherapy:

∙ Predictive CRM \< 2 mm

‣ Or T3c-d (extending ≥ 5 mm beyond the muscularis propria) with extra mural venous invasion (EMVI)

‣ Or T4a-b (except bone and sphincteric invasion).

• NON INCLUSION CRITERIA FOR SCREENING

• Non measurable rectal tumor or not assessed by MRI before inclusion,

• Ultra-low rectal tumor at diagnosis which imposes radiotherapy administration (inferior tumor pole less than 1 cm from the upper part of the levator ani).

• Active cardiac disease including any of the following: a. Congestive heart failure ≥ New York Heart Association (NYHA) class 2 (appendix 4), b. Unstable angina (angina symptoms at rest), new-onset angina (begun within the last 3 months), c. Myocardial infarction less than 6 months before first dose of treatment, d. Cardiac arrhythmias requiring anti-arrhythmic therapy (beta blockers or digoxin are permitted),

• Previous or concurrent cancer that is distinct in primary site or histology from colorectal cancer within 5 years prior to study inclusion, except for curatively treated cervical cancer in situ, non-melanoma skin cancer and superficial bladder tumors \[Ta (non invasive tumor), Tis (carcinoma in situ) and T1 (lamina propria invasion)\],

• Arterial or venous thrombotic or embolic events such as cerebrovascular accident (including transient ischemic attacks), deep vein thrombosis or pulmonary embolism within 6 months before start of treatment.

• WHO performance status 0-1,

• Patient with tumoral regression ≥ 60% and CRM ≥ 1mm,

• No unequivocal evidence on CT-Scan of established metastatic disease,

• General condition considered suitable for radical pelvic surgery and a systemic therapy with Capecitabine

• Adequate hematologic, hepatic, renal and ionogram function assessed within 7 days prior to study treatment a. Platelet count ≥ 100,000/mm3; Hemoglobin (Hb) ≥ 9 g/dL; Absolute neutrophil count (ANC) ≥ 1,500/ mm3 b. Total bilirubin ≤ 1.5 x Upper Limit Normal (ULN), Alkaline phosphatases ≤ 3 x ULN and ASpartate aminoTransferase (AST) and ALanine aminoTransferase (ALT) ≤ 3 x ULN, c. Serum creatinine ≤ 1.5 x ULN or calculated creatinine clearance ≥ 50 ml/min according to Modification of Diet in Renal Disease (MDRD),

• For women of reproductive potential, negative serum beta human chorionic gonadotropin (β-HCG) pregnancy test obtained within 7 days before the start of study treatment. Women not of reproductive potential are female patients who are postmenopausal or permanently sterilized (e.g., tubal occlusion, hysterectomy, bilateral salpingectomy),

• For women of childbearing potential and men, agreement to use an adequate contraception for the duration of study participation and up to 6 months following completion of therapy. Females of childbearing potential who are sexually active with a non-sterilized male partner must use 2 methods, of effective contraception. The investigator or a designated associate is requested to advise the patient on how to achieve an adequate birth control. Adequate contraception is defined in the study as any medically recommended method (or combination of methods) as per standard of care,

• No evidence of chronic or acute ischemic heart disease,

• Willing to participate to the study, and able to give informed consent and to comply with the treatment and follow-up schedules,

⁃ Affiliation to the French Social Security System.