EarlyPostoperative Lactate-to-Preoperative Albumin Ratio with In-Hospital Mortality After Elective Colorectal Cancer Surgery: A Single-Center Retrospective Cohort Study

Background: Risk stratification after colorectal cancer surgery remains challenging. We evaluated whether a perioperative ratio combining immediate postoperative lactate with preoperative albumin is associated with in-hospital mortality after elective colorectal resection. Methods: In this single-center retrospective cohort, 282 patients underwent open elective colorectal resection. The perioperative lactate-to-albumin ratio (LAR) was calculated as arterial lactate (mmol/L) divided by serum albumin (g/dL), and discrimination was assessed by receiver operating characteristic (ROC) analysis with age-adjusted association by Firth’s penalized logistic regression and fixed-model bootstrap validation. Results: Seventeen patients (6.0%) died in hospital, and mortality rose across LAR tertiles (2.1%, 5.3%, and 10.6%; p = 0.014). LAR showed moderate discrimination (AUC 0.73; 95% CI 0.58–0.87; optimism-corrected AUC 0.78), with no evidence of better discrimination than lactate or albumin alone. At the Youden threshold of 0.555, sensitivity was 76.5% and specificity 61.1%. The age-adjusted Firth odds ratio was 1.19 per 0.1-unit increase (95% CI 1.09–1.29). Conclusions: The perioperative lactate-to-albumin ratio was associated with in-hospital mortality after age adjustment in this single-center cohort. Given the small number of deaths and absence of external validation, LAR should be regarded as a candidate marker requiring prospective multicenter validation before clinical application.