51 Positive resection margin is not a determinant for long term survival after resection for colorectal liver metastasis

Abstract Background Hepatic resection together with perioperative chemotherapy is currently the only treatment option that can offer a chance of long-term curative outcome in patients with colorectal liver metastases. The surgical margin status has been considered to be one of the most powerful prognostic factors for overall survival. The aim of this study is to determine whether positive resection margin determine tumor recurrence and influences long-term survival, in the era of aggressive chemotherapy. Methods Clinicopathological outcomes of patients who underwent curative resection for colorectal liver metastases between 2018 and 2023 at the Barts HPB Centre of the Royal London Hospital were assessed. The association between surgical margin status and tumor recurrence was evaluated as well as the impact on the overall survival. Results Of 138 patients undergoing liver resection only for CRLM, hepatic tumor recurrence was identified in 70 patients (51%) with no difference between those having R0 and R1 liver resections (p=.331). Positive resection margins were associated with proximity of tumor to major vascular structures of the liver, whereas negative margins with T4 stage of the primary colorectal cancer. Upon multivariate analysis, R1 margins did not impact overall and disease-free survival but proximity of the tumor to major liver vascular structures, as well as R1 margin of primary CRC resection were significant independent factor negatively affecting the survival outcomes. Conclusion The incidence of hepatic recurrence after hepatectomy for colorectal liver metastases and the survival outcomes are independent of the R1 resection margin status, in the era of systemic therapy.