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

Blood collection times according to specific clinical situations:

* Standard approach
* Combined surgery
* Reverse strategy
* Two-stage hepatectomy

Primary outcomes

• Disease-free survival (DFS) in patients who undergo curative-intent resection of colorectal liver metastasis (CRLM) [Up to 36 months]: DFS is defined as the time from complete surgical resection (following first surgery if one-stage surgery or second surgery if two-stage strategy) to first documented event (relapse or death, whichever occurred first), or until last contact if no event occurs.

Secondary outcomes

• Number of event-free survival (EFS) in patients who undergo curative-intent resection of CRLM. [Up to 4 years]: EFS is defined as time between inclusion until the occurrence of an event: disease progression, relapse, disease progression, or death from any reason.
• Overall survival (OS) n patients who undergo curative-intent resection of CRLM. [Up to 4 years]: OS is defined as the time between inclusion and death. Alive patients will be censored at the last date known to be alive, either during study treatment period or during follow-up period.
• Time to surgical failure (TSF) in patients who undergo curative-intent resection of CRLM. [Up to 4 years]: TFS is defined as the time from initial surgery until the first unresectable recurrence or death from any cause or the date of the last follow-up, at which point data are censored.
• Prognostic value of ctDNA [Up to 4 years]: Prognostic value of ctDNA: * post-operative ctDNA detection, * relative change in ctDNA level after curative resection of CRLM, * ctDNA in different subgroups of patients classified according to the type of surgical strategy (standard approach, combined surgery, reverse strategy, two-staged hepatectomy),
• Prognostic factor(s) for disease recurrence and survival. [Up to 4 years]: Prognostic factor(s) for disease recurrence and survival in patients who undergo curative-intent resection of CRLM.
• Association between ctDNA and clinical features. [Up to 4 years]: To identify the clinical, biological, and pathological factors associated with the ctDNA level.

Sex: All, ages: 18 Years to any

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.

• Maximiliano GELLI, MD, Principal investigator, Department of Digestive Surgery, Gustave Roussy Hospital