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

This study is tracking a blood test called ctDNA (circulating tumor DNA) in people with colorectal cancer who are having surgery to remove liver metastases (tumors that have spread from the colon to the liver). The goal is to see whether this liquid biopsy can predict how well surgery is working and whether cancer is likely to come back. **You may be eligible if...** - You are 18 or older - You have confirmed colorectal cancer that has spread to the liver - Your liver tumors are considered removable or potentially removable by a specialist team - You are scheduled for surgery (with or without chemotherapy beforehand) - You are registered in a national healthcare system (French participants) **You may NOT be eligible if...** - Your liver tumors are definitively not operable - You have received more than 9 cycles of chemotherapy for metastatic disease before surgery - Your primary rectal tumor has not been removed - You have had another cancer in the last 5 years (except non-melanoma skin cancer or cervical carcinoma in situ) Talk to your doctor to see if this trial is right for you.