A Clinical-biological Prospective Cohort of Patients With BRAFV600E-mutated Metastatic Colorectal Cancer

Who May Qualify: 1. Men and women aged 18 years or older 2. diagnosed by tissue sample (biopsy-confirmed) BRAFV600E metastatic colorectal cancer (mCRC), chemotherapy-naive in the metastatic setting or having initiated a first line of chemotherapy in the metastatic setting (except encorafenib-cetuximab treatment) 3. Available tumor tissue sample obtained before inclusion with sufficient tissue left for biological studies. Patients with only fine-needle aspirations are not eligible. 4. Known MMR/microsatellite status (immunohistochemistry \[IHC\] and polymerase chain reaction \[PCR\]) (or under analysis) 5. Patients must have signed a written willing to sign a consent form form prior to any trial specific procedures. If the patients are physically unable to give their written consent, a trusted person of their choice, not related to the investigator or the sponsor, can confirm in writing the patient's consent. 6. Patients must be willing and able to comply with the study procedures 7. The patient must be affiliated to a social security system or benefit of such a system. Who Should NOT Join This Trial: 1. Patient with another cancer concomitantly with the mCRC requiring treatment or influencing the prognosis according to the medical staff. 2. Patients for whom the follow-up will not be assured by the investigator or its team. 3. Any condition that may jeopardize patient participation in the study as well as non-contraception for men and women with child-bearing potential, and pregnancy or breast feeding for women. 4. Persons deprived of their liberty or under protective custody or guardianship. Always talk to your doctor about whether this trial is right for you.