Clinical Scorecard: Risk Assessment Framework for Smoldering Multiple Myeloma by the International Myeloma Working Group
At a Glance
Category
Detail
Condition
Smoldering multiple myeloma (SMM), a transitional stage between MGUS and active multiple myeloma
Key Mechanisms
Presence of serum monoclonal protein, bone marrow plasma cell infiltration, and serum free light chain ratio indicating risk of progression to MM
Target Population
Patients diagnosed with SMM based on 2014 IMWG criteria
Care Setting
Hematology/oncology outpatient and specialized clinical settings
Key Highlights
SMM has a heterogeneous risk of progression to MM: ~10% per year for first 5 years, decreasing thereafter.
Risk stratification models (Mayo Clinic, Spanish Group) identify patients with ≥50% 2-year progression risk using M-protein, BMPC infiltration, sFLC ratio, and immunophenotyping.
Revised IMWG criteria reclassify high-risk SMM patients (BMPCs ≥60%, sFLC ratio ≥100, >1 focal MRI lesion) as MM, prompting earlier treatment.
Guideline-Based Recommendations
Diagnosis
Define SMM by serum monoclonal protein ≥3 g/dL and/or ≥10% bone marrow plasma cells without CRAB symptoms.
Use biomarkers including BMPC infiltration, sFLC ratio, and MRI focal lesions to stratify risk and differentiate from active MM.
Employ risk models incorporating M-protein >2 g/dL, BMPCs >20%, and involved/uninvolved sFLC ratio >20 for individualized risk prediction.
Management
Standard care for SMM remains observation regardless of risk status.
Consider early treatment with lenalidomide ± dexamethasone in high-risk SMM to delay progression and improve overall survival, based on randomized trials.
Reclassify patients meeting high-risk biomarker criteria as MM and initiate therapy accordingly.
Monitoring & Follow-up
Regular follow-up to assess progression to MM or related plasma cell disorders.
Use clinical, laboratory, and imaging assessments to monitor disease status and risk factors over time.
Risks
Risk of progression to MM is highest in first 5 years post-diagnosis and varies by risk stratification.
Heterogeneity in risk models and small patient series limit uniform application; individualized risk assessment is essential.
Patient & Prescribing Data
High-risk SMM patients identified by biomarker criteria and risk models
Early intervention with lenalidomide-based regimens significantly delays progression to MM and improves survival compared to observation.
Clinical Best Practices
Apply validated risk stratification models to identify high-risk SMM patients.
Use revised IMWG criteria to distinguish patients requiring early treatment from those suitable for observation.
Incorporate comprehensive baseline and follow-up assessments including serum M-protein, BMPC percentage, sFLC ratio, and imaging studies.
Engage multidisciplinary teams and consider clinical trial enrollment for high-risk patients.
by María-Victoria Mateos, Shaji Kumar, Meletios A. Dimopoulos, Verónica González-Calle, Efstathios Kastritis, Roman Hajek, Carlos Fernández De Larrea, Gareth J. Morgan, Giampaolo Merlini, Hartmut Goldschmidt, Catarina Geraldes, Alessandro Gozzetti, Charalampia Kyriakou, Laurent Garderet, Markus Hansson, Elena Zamagni, Dorotea Fantl, Xavier Leleu, Byung-Su Kim, Graça Esteves, Heinz Ludwig, Saad Usmani, Chang-Ki Min, Ming Qi, Jon Ukropec, Brendan M. Weiss, S. Vincent Rajkumar, Brian G. M. Durie, Jesús San-Miguel
