Certain findings can help to identify a patient with smoldering multiple myeloma (SMM) who is at high risk for progression.
Patient selection: meets criteria for smoldering multiple myeloma
Risk factors for high risk SMM:
(1) serum monoclonal protein >= 30 g/L (3 g/dL)
(2) IgA SMM
(3) immunoparesis with reduction in 2 uninvolved immunoglobulin isotypes
(4) ratio of serum light chains [(involved) / (uninvolved)] >= 8 but < 100
(5) progressive increase in the monoclonal protein (increase >= 25% over 2 successive measurements within a 6 month period)
(6) clonal plasma cells in bone marrow 50-59% (myeloma shows >= 60%)
(7) high risk cytogenetics: t(4;14), del(17p) or 1q gains
(8) increased circulating plasma cells in the peripheral blood
(9) MRI with diffuse abnormalities or 1 focal lesion
(10) PET-CT shows a focal lesion with increased uptake but no osteolysis
where:
• Also listed is "abnormal plasma cell immunophenotype (>= 95% of bone marrow plasma cells are clonal) and reduction of >= 1 uninvolved immunoglobulin isotypes". The > 95% clonal BMPC seems to exceed the >= 60% criterion for multiple myeloma.
