In order to enable early treatment and prevent the emergence of end-organ damage during the transition from smoldering multiple myeloma (SMM) to MM, the definition of multiple myeloma (MM) was modified in 2014. For a study, researchers sought to determine how much the modified recommendations reduced the occurrence of end-organ damage at the MM progression stage.

About 96 SMM patients participated in the prospective observational cohort research between 2014 and 2020. They had whole-body magnetic resonance imaging (wb-MRI) at baseline and then every six months after that. Twenty-two patients in total advanced to MM during follow-up; 7 (32%) of these patients only met the SLiM criteria without end-organ damage.

Of the seven patients who advanced according to the SLiM criteria, 4 (57%) had >1 focal lesion or a growing focal lesion (FL), and 3 (43%) had a serum-free light-chain ratio ≥100. Out of 22 patients, 15 (68%) still had end-organ damage at the time of progression. The proportion of SMM patients with end-organ damage at the time of MM progression was lowered by one-third as a result of the modified illness criteria. The identification of SMM patients who develop MM without end-organ damage requires the use of wb-MRI.

Reference: onlinelibrary.wiley.com/doi/10.1111/bjh.18232