ctDNA in CRC Patients Undergoing Curative-intent Surgery for Liver Metastases

Inclusion criteria The patient will be included if: 1. Has signed informed consent form and is willing to comply with all study procedures and availability for the study duration, 2. Is ≥ 18 years of age, 3. Has histologically confirmed colorectal adenocarcinoma, 4. Has resected primary tumor or is eligible to primary tumor and CRLM (in case of synchronous metastases) resection within 6 months prior to study inclusion, 5. Has isolated CRLM that is deemed resectable or potentially resectable (extrahepatic metastases excluded, except infracentimetric non-specific lung lesions with largest diameter \<1 cm and maximal number of ≤3) as judged by a multidisciplinary team meeting (based on CT scans of chest, abdomen, and pelvis \[or MRI if CT not possible\]), 6. Is eligible to surgical procedure, 7. Is fit for the chemotherapy-surgery combination treatment, 8. Is registered in a national health care system (Protection Universelle Maladie \[PUMa\] included). Exclusion criteria The patient will be excluded if: 1. Has definitively unresectable CLRM, 2. Had more than 9 pre-operative cycles of chemotherapy for treatment of metastatic disease planned at inclusion, 3. Has not resected primary rectal tumor (low and middle), 4. Has history of another primary cancer within the last 5 years, with the exception of non-melanomatous skin cancer and carcinoma in situ of the cervix, 5. Has no more than two surgical procedures planned for complete resection of primary tumor and/or liver metastases, 6. Has deficient mismatch repair (dMMR)/ microsatellite instability (MSI) tumors treated with immunotherapy, 7. Blood samples cannot be collected if surgical procedure, 8. Is pregnant or breastfeeding, 9. Cannot be followed-up due to geographical, social, or psychic conditions, 10. Has medical or psychiatric condition or occupational responsibilities that may preclude compliance with the protocol, 11. Is under guardianship, curatorship, or under the protection of justice.