Overestimation of multiple myeloma survival from cancer registry data

Surveillance, Epidemiology, and End Results (SEER) multiple myeloma (MM) survival statistics that have been used to guide MM management and control have been systematically overestimated due to the inclusion of smoldering multiple myeloma (SMM), according to researchers from Washington University School of Medicine (St. Louis, MO) and Yale School of Public Health (New Haven, CT). Using the latest SEER release, the authors state that in 2016, 77.9% out of 5,495 patients reported as overall MM were symptomatic MM whereas 10.9% were SMM. Median survival was 65.8 months for overall MM versus 56.8 months for symptomatic MM (p<0.001). Inclusion of SMM overestimated MM survival by 9 months. Five-year relative survival estimates from 2015-2021 were 61.6% for overall MM, 57.9% for symptomatic MM, and 88.3% for SMM, versus SEER’s reported 62.4%. The authors conclude that survival statistics for symptomatic MM and SMM should be reported separately to guide MM management and prevention at the population level.