Prognostic value of hematological markers for anastomotic leakage diagnosed after postoperative day 5 following laparoscopic surgery for colorectal cancer

Background Anastomotic leakage (AL) is a common complication following colorectal cancer surgery, yet accurate and unified diagnostic criteria remain lacking. Methods This retrospective study included 360 patients who underwent laparoscopic colorectal resection with one-stage anastomosis at the First Affiliated Hospital of Kunming Medical University between October 2019 to December 2023. Hematocrit-to-albumin difference (HCT-ALB), neutrophil-to-albumin ratio (NAR), and neutrophil-to-lymphocyte ratio (NLR) on postoperative days (POD) 1, 3, and 5 were compared between patients with and without AL. This study specifically aimed to evaluate the predictive performance of these markers for AL occurring after POD 5. Results Compared to the non-AL group, the AL group exhibited significantly higher HCT-ALB, NAR, and NLR values on POD 3 and 5 ( P < 0.05), except for NLR on POD 1. Multivariate analysis identified rectal tumor location, HCT-ALB and NLR on POD 3, and NAR and NLR on POD 5 as associated factors of AL, while preoperative ALB, HCT-ALB on POD1 and POD5, and NAR on POD1 and POD3 showed weaker associations ( P > 0.05). The best predictors were NAR on POD 5 (AUC = 0.910, cut-off = 2.09) and NLR on POD 5 (AUC = 0.885, cut-off = 7.19). Due to the exploratory nature of this study and the potential for collinearity between these inflammatory markers, these results should be interpreted with caution. Conclusion Tumor location (rectum), HCT-ALB and NLR on POD 3, and NAR and NLR on POD 5 may serve as reliable indicators for AL, thus enabling early identification and timely intervention to improve postoperative outcomes after colorectal surgery.