Predictive Significance of Serum Beta 2-Microglobulin Levels and M-Protein Velocity for Symptomatic Progression of Smoldering Multiple Myeloma

Background: Smoldering multiple myeloma (SMM) has been defined as precursor state to symptomatic multiple myeloma (MM). Mayo Clinic demonstrated that the presence of bone marrow plasma cells (BMPC) ≥ 10% and M protein levels ≥ 3 g/dL significantly associated with early progression to symptomatic MM and the serum free-light chain (FLC) ratio of < 0.125 or 8 < was an important additional predictors of progression. PETHEMA showed that the proportion of aberrant plasma cells (aPCs) within the BMPC > 95% as assessed by flow cytometry was another important variable for progression. However, NIH demonstrated the discordance of these two risk models. The aim of this project is to develop the method to predict the symptomatic progression more definitely by simple parameters, usually available at medical practice.