Currently, chemotherapies are empirically administered to patients treated for colorectal cancer (CRC). Selection is based on the efficacy of a protocol previously determined on the largest number (consensus treatment), the decision-making process being weighted by patient's intrinsic criteria. However, each patient is unique, due to the inter- and intratumoral heterogeneity inherent in any cancer, partly explaining the unsatisfactory response rates observed for available chemotherapies. Functional sensitivity tests offer the possibility to adapt the treatment to each patient: they are based on an ex vivo study of the responses of the tumor cells (survival / death) to the different molecules / therapeutic combinations (chemotherapy or targeted therapy) likely to be administered to the patient. This response, translated into a tumor-specific sensitivity profile, can be used by the clinicians to determine the most appropriate therapeutic protocol. By increasing the therapeutic efficacy from the first line and reducing the deleterious side effects associated with multiple drug cycles, the sensitivity test transforms the consensus approach into personalized medicine, providing patients with improved progression free survival (PFS) associated with an improvement in the quality of life. Oncomedics has developed Oncogramme®, a CE-labeled in vitro diagnostic medical device that has already demonstrated the ability to predict chemosensitivity in a recent pilot study of metastatic CRC (prediction with 84% chance of success of tumor sensitivity to chemotherapy, vs. 50% maximum for chemotherapy administered according to the consensus method). The hypothesis that patients treated with a metastatic CRC for which systemic chemotherapy is adapted using Oncogramme® have better response rates, PFS and quality of life than patients treated according to usual practice, with optimization of the costs of care. To our knowledge, this is the only fully standardized test available, where each step and reagents of the procedure are mastered. The reliability of the procedure makes it possible to render a personalized result for each patient in 97% of the cases. In addition, the analysis is specifically centered on tumor cells using a method using fully defined, developed and validated media and reagents for each cancer, including CRC. The method of revealing the effect of the therapies identifies the proportion of dead cells in each condition, whatever their physiological state (proliferation / quiescence), by determining the percentage of living and killed cells, thus ensuring high sensitivity

Inclusion Criteria:

• Age ≥ 18 years
• Patient with metastatic colon or rectal adenocarcinoma (Stage IV) who can benefit from standard systemic chemotherapy (monotherapy based on 5-FU, polychemotherapy type FOLFOX, FOLFIRI, FOLFIRINOX, associated or not with targeted therapies Adapted to the expression of BRAF and RAS, whatever the route of administration of the proposed, oral or intravenous therapies)
• Metastatic CRC diagnosed preoperatively on imaging or per-operative on macroscopic findings and proved by histological analysis (biopsy or surgical excision and if possible biopsies or excrescence on the metastatic sites)
• Measurable metastases according to RECIST
• Chemotherapy for curative or palliative purposes
• Patient with consent.
• Affiliate or beneficiary of a social security scheme.

Exclusion Criteria:

• Formal contraindication to paraclinic exploration essential for patient follow-up
• Exclusive use of radiotherapy, targeted therapy, immunotherapy or hormone therapy, exclusive palliative support
• Patient with an absolute contraindication to the administration of chemotherapy
• Pregnant, lactating or non-contraceptive women for childbearing age women
• Patient with a difficulty of understanding the protocol
• Patient under protective measures (guardianship, curatorship, etc.).

The result of Oncogramme® will not give to the patient.