Several risk scores established to help predict which patients with smoldering multiple myeloma are most likely to progress using easily available parameters were equally useful to stratify high-risk patients in a group of real-life patients from a single community cancer center, a new study found.1
“In particular, free light chain evaluation as well as plasma cell infiltration rate both work well and are confirmed to be reliable and easily applicable tools for estimating the risk of smoldering myeloma evaluation,” researchers wrote.
In the study, a group of Italian researchers looked at the 2014-updated International Myeloma Working Group (IMWG) diagnostic criteria and several other current risk models and applied them to a group of 75 unselected patients with smoldering multiple myeloma seen between 2000 and 2015.
For example, looking at the 2007 Mayo Clinic risk model, which looked at bone marrow plasma cells (BMPC) infiltration rate and amount of serum monoclonal component, the majority of patients fell into the intermediate risk group (87.3%). This model failed to identify a significant difference in outcome between groups.
However, when the researchers used the updated Mayo Clinic risk model, which added free light chain testing, 48% were low risk, 46% were intermediate risk, and 6% were high risk. With this model there was a significant difference in time to progression among the groups.
The researchers also looked at the Czech risk model, the University of Pennsylvania risk model, a Danish risk model, and the 20-20-20 Mayo risk model. Taken together, these models were clinically useful for identifying smoldering multiple myeloma patients at higher risk of progression with Harrell’s C indexes ranging from 0.57 to 0.68 with overlapping 95% confidence intervals.
Univariate analysis of the impact of baseline clinical characteristics on time to progression indicated that increasing BMPC infiltration rate, abnormal free light chain ratio, and immunoparesis were all associated with a shorter time to progression.
Cocito F, Mangiacavalli S, Ferretti VV, et al. Smoldering multiple myeloma: the role of different scoring systems in identifying high-risk patients in real-life practice [published online June 6, 2019]. Leuk Lymphoma. doi: 10.1080/10428194.2019.1620948