Comparison of Myosteatosis, Myopenia, Must Tool and Subcutaneous Adipose Tissue as Risk Factors for Anastomotic Leak in Patients with Colorectal Cancer

INTRODUCTION Myosteatosis, myopenia, the Malnutrition Universal Screening Tool (MUST), and the amount of subcutaneous adipose tissue have been identified as significant risk factors for postoperative complications in patients with colorectal cancer. However, cut-off points to predict anastomotic dehiscence and severe complications have not been established. METHODS A prospective study was carried out in patients undergoing resection of colorectal tumors with anastomosis between June 2022 and November 2024. The MUST score, average psoas density, muscle mass, and amount of subcutaneous tissue at the L3 level on computed tomography (CT) were documented. Anastomotic dehiscence and severe postoperative complications according to the Clavien-Dindo (CD) classification were recorded. RESULTS A total of 250 patients were included. Only myosteatosis showed a statistically significant association with the occurrence of severe complications (AUC: 0.788; p < 0.001) and anastomotic dehiscence (AUC: 0.881; p < 0.001) on ROC curves. Additionally, myosteatosis was significantly associated with postoperative complications (RR: 3.448, 95% CI: 2.695–4.347, p < 0.01) and severe complications (RR: 7.88, 95% CI: 4.27–14.59, p < 0.01) before hospital discharge. CONCLUSIONS Myosteatosis, assessed through radiologic density on preoperative CT imaging, is a significant predictor of severe postoperative complications (CD ≥ III) in colorectal cancer patients, as well as anastomotic dehiscence. Identifying myosteatosis may help clinicians recognize high perioperative risk patients early and improve preoperative planning.