The prognostic impact of neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) in patients with distal bile duct cancer

Background A growing body of evidence suggests that inflammatory response markers such as the neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) are associated with outcomes of various malignancies. However, no study has reported the prognostic value of NLR and LMR in patients with distal bile duct cancer (DBDC) to date. We investigated the prognostic significance of these inflammatory markers in patients with DBDC who underwent radical resection. Methods The study included 40 patients diagnosed with DBDC who underwent pancreaticoduodenectomy at Narita Red Cross Hospital between January 2000 and December 2017. The cutoff values for these markers were determined by receiver operating characteristic curve analysis. Survival curves are estimated for each group in the study considered separately using the Kaplan-Meier method. The association between overall survival (OS) and the NLR, LMR, and other prognostic factors was investigated using log-rank test and multivariate Cox proportional hazards regression analysis. Results Corresponding to the point with the maximum combined sensitivity and specificity on the ROC curve, the best cutoff value for NLR and LMR was determined to be 3.14 and 4.55, respectively. Most clinicopathological factors were not associated with the NLR and LMR based on these cutoff values. However, serum albumin levels were associated with both the NLR and LMR (P = 0.011 and P = 0.023, respectively), and serum carbohydrate antigen 19-9 (CA 19-9) levels were also associated with the LMR (P = 0.030). Univariate analysis showed that a high NLR (P < 0.001), low LMR (P = 0.002), hypoalbuminemia (P = 0.004), high serum CA 19-9 levels (P = 0.008), and lymph node metastasis (P = 0.033) were significantly associated with poor survival rates. Multivariate analysis showed that a high NLR (hazard ratio 5.799, 95% confidence interval 1.188-28.32, P = 0.030) and a low LMR (hazard ratio 4.837, 95% confidence interval 1.826-2.331, P = 0.025) were independent prognostic factors for OS. Conclusion Both NLR and LMR may serve as significant independent preoperative prognostic indicators of disease in patients with DBDC who undergo radical resection.