The Neutrophil-to-Lymphocyte Ratio as a Marker of Lymph Node Status in Patients with Rectal Cancer

Abstract

Aim: The aim of the study was to investigate the role of the neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker of rectal cancers. Methods: We undertook a retrospective review of patients with rectal cancer. Pre-treatment NLR was assessed for association and predictive values against clinicopathological staging and post-treatment outcomes. Results: A total of 140/180 cases were included in the final analysis [male:female 2:1; mean age 68 years (interquartile range 58-75)]. The pre-operative mean NLR was 5.4 ± 6.8. There was a strong positive correlation between NLR and C-reactive protein (Spearman's rho 64.3%, p < 0.001). A high NLR was associated with a positive nodal status on MRI (5.2 vs. 3.8, p = 0.03) and histopathological (4.8 vs. 3.8, p = 0.02) assessment. The NLR showed an average value for predicting MRI and pathological nodal status on receiver operating characteristic analysis [area under the curve = 0.72 (95% CI = 0.54-0.91), p = 0.031 and area under the curve = 0.64 (95% CI = 0.52-0.077), p = 0.021, respectively]. On multivariate analysis, the total lymph node retrieved at operation was the best predictor of pathological nodal involvement; NLR did not show any predictive value. Patients with an NLR >4 showed reduced recurrence-free (60 vs. 86 months, p = 0.52) and overall survival (57 vs. 84 months, p = 0.40) without statistical significance. Conclusion: Raised pre-treatment NLR may indicate nodal involvement in patients with rectal cancer.