Propensity-score matched outcomes of resection of stage IV primary colon cancer with and without simultaneous resection of liver metastases.

There is controversy in the best management of colorectal cancer liver metastasis (CLM). This study aimed to compare short-term and survival outcomes of simultaneous resection of CLM and primary colon cancer compared to resection of only colon cancer. This retrospective matched cohort study included patients from the National Cancer Database (2015-2019) with stage IV colon adenocarcinoma and synchronous liver metastases who underwent colectomy. Patients were divided into two groups: colectomy-only (resection of primary colon cancer only) and colectomy-plus (simultaneous resection of primary colon cancer and liver metastases). The groups were matched using the propensity score method. The primary outcome was short-term mortality and readmission. Secondary outcomes were conversion, hospital stay, surgical margins, and overall survival. 4082 (37.6%) of 10,862 patients underwent simultaneous resection of primary colon cancer and liver metastases. After matching, 2038 patients were included in each group. There were no significant differences between the groups in 30-days mortality (3.1% vs 3.8%, p = 0.301), 90-days (6.6% vs 7.7%, p = 0.205) mortality, 30-days unplanned readmission (7.2% vs 5.3%, p = 0.020), or conversion to open surgery (15.5% vs. 13.8%, p = 0.298). Patients in the colectomy plus group had a higher rate of lower incidence of positive surgical margins (13.2% vs. 17.2%, p = 0.001) and longer overall survival (median: 41.5 vs 28.4 months, p < 0.001). Synchronous resection of CLM did not increase the rates of short-term mortality, readmission, conversion from minimally invasive to open surgery, or hospital stay and was associated with a lower incidence of positive surgical margins.