Prognostic value of the inverse platelet to lymphocyte ratio (iPLR) in patients with multiple myeloma who were treated up front with a novel agent-containing regimen.

Recently, reactive thrombosis or platelet to lymphocyte ratio has been reported as a strong predictor of poor prognosis in various types of cancer. However, a study investigating the relationship between platelet counts and thrombopoietic cytokines suggested that low platelet could be important in multiple myeloma (MM), which means platelet count decreased in advanced International Staging System (ISS) stage. Therefore, we developed inverse platelet to lymphocyte ratio (iPLR) and assessed the prognostic value of iPLR in patients with MM. We retrospectively analyzed 283 patients who were treated up front with a novel agent-containing regimen. Patients were classified into three groups based on hazard ratio (HR) according to iPLR: low iPLR (group 1), middle iPLR (group 2), and high iPLR (group 3). Over a median follow-up of 34.8 months, staging by iPLR group had predictive value for progression-free survival (PFS) and overall survival (OS). In addition, staging by iPLR group was a reliable method to predict for survival in patients who presented with renal failure (eGFR<60 mL/min/1.73 m2) and in elderly patients. Multivariate analyses demonstrated that staging by iPLR group was associated with PFS and OS in patients with MM. In conclusion, this study suggested that iPLR is a simple and reliable inflammatory prognostic factor in the era of novel agents.