Pretreatment platelet-lymphocyte ratio versus neutrophil-lymphocyte ratio in the prognosis of multiple myeloma: a single center retrospective study

As representatives of inflammation factors, Neutrophil to lymphocyte ratio (NLR) and Platelet-lymphocyte ratio (PLR) have both showed good prognostic significance in various malignancies. In this study, we compared the usefulness of PLR with that of NLR for predicting outcomes of patients with multiple myeloma (MM). In this study, 166 MM patients (88 males and 78 females, average age: 61.6 +/- 10.8 years) were retrospectively observed between January 2009 and December 2015. Their baseline platelet, lymphocyte, neutrophil counts and other clinical data were collected and the clinical characteristics were subsequently compared between different subgroups. Based on NLR and PLR, patients were divided into groups of high NLR (> 1.97) and low NLR (<= 1.97), high PLR (> 98.45) and low PLR (<= 98.45), respectively. Our result showed that high NLR was not always consistent with other unfavorable clinical variables though it did show a significant correlation with serum creatinine, while a decreased PLR was closely related with numerous unfavorable clinical parameters, and it was negatively related with tumor burden and renal dysfunction. More importantly, NLR was neither related with patients' overall survival (OS) nor progression free survival (PFS), while PLR showed an excellent correlation with patients' OS and PFS, thought both of them showed negative correlation with red blood cell width distribution (RDW), another readily available predictive index for MM. Furthermore, Cox univariate and multivariate regression analysis found that PLR was an independent prognostic factor for MM. In conclusion, pretreatment PLR might be superior to NLR to be predictive of survival in myeloma patients because of its better stability and reliability.