This prospective, non randomized multicenter phase II study, will determine the feasibility of individualized dose of irinotecan with the UGT1A1 polymorphism, in patients with metastatic colorectal cancer treated with FOLFIRI.

Inclusion Criteria:

• Colorectal cancer histologically or cytologically proven
• Indication of treatment according to the FOLFIRI + / - bevacizumab or cetuximab or panitumumab
• Age> 18 years
• Presence of at least one measurable target by RECIST
• Life expectancy> 3 months
• Satisfactory biological functions (renal, hepatic and hematologic)
• Affiliation to a social security scheme (or be the beneficiary of such a plan) under the terms of the Act of August 9, 2004
• Patient has signed, after informing the informed consent form

Exclusion Criteria:

• Patients of childbearing age and not using effective contraception during treatment and for at least three months after the end of treatment with irinotecan and at least six months after the end of treatment with bevacizumab, cetuximab or panitumumab and patient pregnant or nursing
• Patient with another pathology deemed incompatible with the entry in the protocol
• Prior treatment in metastatic
• Patients taking antiepileptic
• Allergic reaction or intolerance to irinotecan
• Heart failure , kidney , bone marrow , liver or respiratory
• Higher bilirubin 1.5 times the upper limit of normal
• Significant psychiatric or neurological abnormality
• Infectious syndrome requiring treatment with antibiotics or antiviral long-term
• Patients with chronic inflammatory bowel disease and / or bowel obstruction
• Contraindication Association St. John's wort and yellow fever vaccine
• Against Heart indication 5-FU
• Concurrent treatment with a drug test , participation in a clinical trial within <30 days
• Patient refused to sign the consent