Reproduced from Rajkumar et al.¹⁸ 

Note that the term smoldering multiple myeloma excludes patients without end-organ damage who meet revised definition of multiple myeloma, namely clonal bone marrow plasma cells ≥60% or serum FLC ratio ≥100 (plus measurable involved FLC level ≥100 mg/L), or more than one focal lesion on magnetic resonance imaging. The risk factors listed in this table are not meant to be indications for therapy; they are variables associated with a high risk of progression of SMM, and identify patients who need close follow-up and consideration for clinical trials.

*Increase in serum monoclonal protein by ≥25% on 2 successive evaluations within a 6 month period.