Main objective : evaluation the margin status (<1mm, 1-4mm, 5-9mm, >10mm) on the survival and recurrence in colo-rectal liver metastases surgery.~Secondary objectives include :~Evaluate potentiel effects of neo-adjuvant chemotherapy, portal embolisation, and evaluate potentiel bias such as size and number of liver metastases, TNM status of original tumor, timing between primary and metastasis, and extra-hepatic disease.~Methods :~A retrospective cohort study is built where all patients undergoing liver surgery for colorectal liver metastases between 2011 and 2015 are analysed. Subjects are separated in groups according to their margin status. The local and distal recurrence rates are measured and well as survival. Data is obtained through our hospital data management system. Inclusion criterias include age over 18, primary colorectal cancer metastatic to the liver, having undergone surgery between 2011 and 2015, available pathology reports with required data, available radiologic follow-up. Exclusion criterias include repeat liver resection, documented grossly positive margins (R2 resection), and unavailable pathologic information and follow-up. Using survival as primary outcome (Kaplan Meier) and considering 25% potential loss to follow-up, we calculated a sample size. Since this a retrospective study, no patient is directly contacted. Data will is handled by the surgery resident responsible for the project as well as by research assistants. Statistical analysis are performed accordingly.
We retrospectively looks at the impact of the margin status and its size in mm on the recurrence rate in colo-rectal liver metastasis surgery.