Let’s See Day Three: Association and Potential Discriminatory Value of Selected Inflammatory and Immunonutritional Biomarkers for Postoperative Morbidity After Minimally Invasive Colorectal Cancer Surgery

Background: Composite immunonutritional biomarkers reflecting systemic inflammation, nutritional status, and immune competence have emerged as promising tools for perioperative risk stratification in colorectal cancer (CRC). However, their prognostic value during the perioperative period following minimally invasive CRC surgery remains unresolved. This study aimed to evaluate the association between perioperative inflammatory biomarkers, including the neutrophil-to-lymphocyte ratio (NLR), hemoglobin–albumin–lymphocyte–platelet (HALP) score, and Host Index (H-index), and short-term postoperative outcomes after minimally invasive colorectal cancer surgery. Methods: This retrospective single-center study included 105 patients who underwent minimally invasive curative-intent surgery for CRC between 2023 and 2025. Biomarkers were assessed preoperatively and during the first four postoperative days. Severe postoperative morbidity was defined as a Comprehensive Complication Index (CCI) ≥ 20.9. Results: Among all parameters, NLR measured on postoperative day 3 demonstrated the highest apparent discriminatory ability for severe complications (AUC = 0.87, 95% CI: 0.74–0.95; sensitivity 91.7%; specificity 73.7%). Preoperative HALP was the most informative preoperative marker (AUC = 0.78, 95% CI: 0.66–0.87; sensitivity 76.5%; specificity 87.7%). Conclusions: Perioperative inflammatory and immunonutritional biomarkers are associated with postoperative morbidity following CRC surgery. Preoperative HALP and postoperative day 3 NLR demonstrated the strongest apparent discrimination for CCI ≥ 20.9; however, these findings require confirmation in larger, independent prospective cohorts.