The prognostic value of the ratio of neutrophils to lymphocytes before and after intensity modulated radiotherapy for patients with nasopharyngeal carcinoma

This study aimed to determine the impact of the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) on the prognosis of nasopharyngeal carcinoma (NPC) before and after intensity modulated radiotherapy (IMRT). Pre/post-treatment and changes in inflammatory biomarker levels of 207 patients who were diagnosed with NPC and received IMRT between January 2012 and December 2014 were analyzed, and the cellular biomarker analyses were from patient blood. ROC (receiver operating characteristic) analysis was used to decide the optimal cutoff values of NLR and changes in NLR (ΔNLR) and PLR (ΔPLR). The Kaplan–Meier and logarithmic rank methods were used to compare overall survival times between groups. Univariate analysis was used to investigate the effects of age, gender, histology, Karnofsky performance score (KPS), TNM stage, clinical stage, course of disease and lymphocyte, neutrophil and platelet counts as well as alkaline phosphatase (ALP) levels on the prognosis of NPC. The independent predictors of OS were determined by Cox multivariate regression analysis. The optimal cut-off values of NLR, PLR, ΔNLR and ΔPLR were 2.49, 155.82, 1.80, and 100.00, respectively. These were used to classify patients into high (NLR > 2.49) and low NLR groups (NLR < 2.49); high (PLR>155.82) and low (PLR < 155.82) PLR groups; high (ΔNLR>1.80) and low ΔNLR groups (ΔNLR < 1.80); high (ΔPLR > 100.00) and low ΔPLR groups (ΔPLR < 100.00). TNM stage, clinical stage and ALP levels were highly correlated with high NLR and PLR. Cox multivariate regression analysis suggested that the ΔNLR (HR = 2.89, 95% CI: 1.33∼2.78) was independent of the characteristics for NPC. As a novel inflammatory index, ΔNLR appears to have some predictive power for the prognosis of patients with NPC.