Clinical Research Directory

Inclusion Criteria: * Patient with histologically confirmed metastatic colorectal cancer * Patient treated in the first line by one of the treatments below and according to a bi-monthly schema for cetuximab: FOLFIRI (elvorin + 5 Fluorouracil + irinotecan) ou FOLFOX (elvorin + 5 Fluorouracil + oxalplatin) + Cetuximab\* (Erbitux) ; FOLFIRI ou FOLFOX + Panitumumab (Vectibix); FOLFIRINOX ou FOLFOXIRI ((elvorin + 5 Fluorouracil + oxaliplatin + irinotecan) + Cetuximab\* (Erbitux); FOLFIRINOX ou FOLFOXIRI + Panitumumab (Vectibix) For patient treated cetuximab administration will be bi-monthly * Patient with at least one evaluable metastatic target according to RECIST 1.1 (Response Evaluation Criteria in Solid Tumors) * Wild RAS (rat sarcoma viral oncogene homolog) status detected by standard tissue test, on primary tumor and / or metastasis * Wild BRAF (murine sarcoma viral oncogene homolog B) status detected by standard tissue test, on primary tumor and / or metastasis * Man or woman\> 18 years old * Signed informed consent before any specific procedure to study * Patient affiliated to the social security or equivalent Exclusion Criteria: * Previous treatment with an anti-EGFR (epidermal growth factor receptor) * Patient with a multifocal primary tumor * RAS (rat sarcoma viral oncogene homolog) status mutated or not detectable on tissue analysis * BRAF (murine sarcoma viral oncogene homolog B) status mutated or undetectable on tissue analysis * Patient receiving adjuvant chemotherapy or radiotherapy within \<14 days * History of other cancer in the last 5 years (except in-situ carcinoma of the cervix and cutaneous carcinoma excluding melanoma treated optimally) * Blood transfusion (whole blood, red blood cell, platelets...) in the previous week * Patients with psychological, familial, sociological or geographic conditions potentially not favorable to the good observance of the study protocol and the follow-up * Legal incapacity or limited legal capacity Participation in another interventional clinical trial - biomedical research (therapeutic strategy type) is not excluded provided that it is use an Anti-EGFR with a AMM (marketing authorization), (Cetuximab - Panitumumab) with a dose and a standard administration rhythm (according to the AMM).