Perioperative Albumin and Postoperative Day 1 Lymphocyte-to-Monocyte Ratio Predict Superficial Surgical Site Infection After Colorectal Cancer Surgery

Background: Surgical site infection (SSI) is a common complication after colorectal cancer (CRC) surgery. Although inflammation-based biomarkers have been investigated as prognostic indicators in CRC, their value for predicting superficial SSI using early postoperative laboratory findings remains unclear. We evaluated the utility of routinely available perioperative biomarkers for early prediction of superficial SSI after curative CRC surgery. Methods: This retrospective study included 488 patients who underwent elective curative resection for CRC. Preoperative and postoperative day (POD) 1 laboratory parameters, including serum albumin and inflammation-based biomarkers, were evaluated. Receiver operating characteristic curve analysis was performed to determine optimal cutoff values, followed by separate multivariable logistic regression analyses for preoperative and POD1 variables. Results: Superficial SSI developed in 66 patients (13.5%). A preoperative serum albumin level ≤3.70 g/dL was the only independent preoperative risk factor for superficial SSI (odds ratio [OR], 2.340; 95% confidence interval [CI], 1.166–4.695; P = 0.017). On POD1, a serum albumin level ≤2.80 g/dL (OR, 2.113; 95% CI, 1.021–4.376; P = 0.044) and a lymphocyte-to-monocyte ratio ≤4.60 (OR, 3.598; 95% CI, 1.559–8.302; P = 0.003) independently predicted superficial SSI. A combined model using preoperative serum albumin, POD1 serum albumin, and POD1 lymphocyte-to-monocyte ratio achieved an AUC of 0.691 (95% CI, 0.619–0.763), with 51.5% sensitivity and 80.3% specificity. Conclusions: Preoperative hypoalbuminemia and lower POD1 serum albumin and lymphocyte-to-monocyte ratio were independently associated with superficial SSI after curative CRC surgery. Assessment of these biomarkers may facilitate early identification of high-risk patients and support targeted preventive strategies.