The Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Patients with Multiple Myeloma: A Retrospective Study

Abstract

Background: The neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) have been shown to serve as simple and inexpensive prognostic markers for various conditions such as colorectal cancer, gastric cancer, lung cancer, advanced heart failure, and other cardiovascular diseases [1-3]. However, limited data exist about the significance of the NLR and PLR in patients with multiple myeloma (MM).Objective: The objective of this study is to determine the prognostic significance of the NLR and PLR in multiple myeloma patients in terms of survival.Methods: A retrospective chart review study was conducted for 175 patients who met the criterion of diagnosis for MM between January 2004 and September 2014. All subjects with 1) Acute infection 2) human immunodeficiency virus infection 3) chronic liver disease 4) collagen vascular disease 4) previous or concomitant other malignancies 5) primary/secondary thrombocytopenia 6) chronic anti-inflammatory medication user, will be excluded from our study. After excluded 14 patients, data from 161 patients were analyzed. The relationship between NLR and PLR, and baseline characteristics, laboratory parameters, overall survival, staging and subtype of Multiple Myeloma will be analyzed using Chi-square test or independent t-test as appropriate. The NLR and PLR were obtained at the time of diagnosis of MM. The optimum cut-off point of the NLR and PLR was determined based on the receiver operating characteristic (ROC) curve. Pearson's correlation coefficient (r) was computed for the correlation between the NLR and the PLR. Overall survival was calculated using the Kaplan-Meier method. Univariate and multivariate analyses using Cox proportional hazards regression models were performed to evaluate the independent prognostic significance of the NLR.Results: The median age of diagnosis was 69 years. Patients were divided into high and low NLR groups and high and low PLR groups, according to cut-off points from the ROC curve for NLR and PLR, which were 2.78 and 155.58, respectively. There was significant positive correlation between the NLR and PLR (r = 0.312; P = 0.000)(figure 1). Patients in the high NLR group is more likely to be male (P=0.002), has lower Hb level (P=0.001), has lower GFR (P=0.003), has lower albumin level (P=0.002), has higher WBC (P=0.013), has higher B2-microglobulin level (P=0.026), and has higher staging (P=0.001). Patients in the high PLR group is more likely to have a lower albumin level (P=0.009) and higher staging (P=0.028). The high NLR group experienced inferior median survival compared to the lower NLR group (37 vs. 66 months; log rank p-value of 0.005)(figure 2a). However, there were no statistical differences in median survival between high and low PLR (45 vs. 62 months; P = 0.077)(figure 2b). Multivariate analysis demonstrated that NLR is an independent predictor for overall survival for MM patients (HR 5.090; P = 0.002).Conclusions: We demonstrated that the NLR, but not the PLR, is an independent prognostic factor for overall survival in MM.