A study with 1996 patients with smoldering multiple myeloma (SMM) established a risk stratification system to predict progression to multiple myeloma (MM) within two years. Three key factors – serum M-protein over 2 g/dL, free light-chain ratio above 20, and more than 20% bone marrow plasma cell infiltration – were identified. Patients were categorized into low (6% risk), intermediate (18% risk), and high (44% risk) groups based on these factors. Incorporating cytogenetic abnormalities, four risk groups were defined, with progression risks ranging from 6% to 63%. The study also developed a scoring tool for a more personalized risk assessment, with progression risks from 3.8% to 73% based on a total risk score.

The results showed that patients with a total risk score of 0-4 had a 3.8% risk of progression, while those with higher scores had significantly increased risks, up to 73% for scores above 12. The study’s findings emphasize the importance of these factors in predicting MM progression, aiding in early intervention and treatment planning.

Reference: Mateos MV, Kumar S, Dimopoulos MA, et al. International Myeloma Working Group risk stratification model for smoldering multiple myeloma (SMM). Blood Cancer J. 2020 Oct 16;10(10):102. doi: 10.1038/s41408-020-00366-3. PMID: 33067414; PMCID: PMC7567803.