Prediction model for SMM or worse may be used to defer bone marrow sampling in persons with MGUS

 

Using a trial of persons with monoclonal gammopathy of undetermined significance (MGUS), researchers developed a prediction model that accurately predicts the presence of 10 percent or more bone marrow plasma cells (BMPC) and therefore a diagnosis of smoldering multiple myeloma (SMM) or multiple myeloma (MM) by bone marrow criteria in persons presumed to have MGUS. The study is published in Annals of Internal Medicine. 

MGUS and SMM are asymptomatic precursor conditions to multiple myeloma and related disorders. Smoldering multiple myeloma is distinguished from MGUS by 10 percent or greater BMPC on sampling, has a higher risk for progression, and requires specialist management. An invasive bone marrow sample is required to distinguish between persons with presumed MGUS and SMM. A possible solution is to develop a model that uses commonly available laboratory parameters to predict the probability of SMM or worse. 

Researchers from the University of Iceland developed a multivariable prediction model to predict if a person with presumed MGUS has 10% or greater BMPC may be eligible for a bone marrow sample using data from 1043 persons with IgG, IgA, light-chain, and biclonal MGUS detected by screening and an interpretable bone marrow sample. The authors found that the model accurately predicts the presence of 10 percent or more BMPC and therefore a diagnosis of SMM or MM by bone marrow criteria in persons presumed to have MGUS. According to the authors, their model has the potential to both decrease the number of persons unnecessarily exposed to this safe but invasive procedure by facilitating shared decision making, allowing for personalized care of MGUS by applying different risk thresholds depending on each unique case. 

 

Media contacts: For an embargoed PDF, please contact Angela Collom at [email protected]. To speak with the corresponding author, Elías Eyþórsson, MD, PhD, please contact [email protected].