Neutrophil-to-Lymphocyte Ratio as an Early Predictor of Symptomatic Anastomotic Leakage in Patients after Rectal Cancer Surgery: A Propensity Score-Matched Analysis.

Background: This study aimed to explore the role of postoperative neutrophil-to-lymphocyte ratio in predicting symptomatic anastomotic leakage in patients who underwent laparoscopic low anterior resection for rectal cancer. Methods: In this retrospective cohort study, we analyzed data of patients who underwent laparoscopic low anterior resection from May 2009 to May 2019. A receiver operating characteristic curve analysis was performed to evaluate the cut-off values with the best predictive efficacy of a symptomatic anastomotic leakage. In addition, a propensity score-matched analysis was performed by considering all covariate variables, and 61 patients with or without symptomatic anastomotic leakage were included in the analysis. Results: The present study included 306 patients; of these, 17 (5.56%) developed symptomatic anastomotic leakage after surgery. On postoperative day 5, compared with patients without symptomatic anastomotic leakage, those with leakage had significantly higher neutrophil-to-lymphocyte levels. Notably, a neutrophil-to-lymphocyte cut-off score of 6.54 indicated the best area under the curve of 0.818 (95% confidence interval: 0.697−0.940, p < 0.001) in predicting symptomatic anastomotic leakage, with a sensitivity and specificity of 76.5% and 79.4%, respectively. Conclusions: Although evidence for the predictive role of neutrophil-to-lymphocyte ratio is accumulating, it remains inconclusive. In addition, neutrophil-to-lymphocyte levels should be considered a predictive biomarker for symptomatic anastomotic leakage; however, it can more accurately be viewed as an adjunct that helps increase the clinical suspicion of emerging symptomatic anastomotic leakage.