Asymptomatic Incidence of Monoclonal Gammopathy of Undetermined Significance and Preclinical Duration to Myeloma Diagnosis: A Modeling Study.

Background: Monoclonal gammopathy of undetermined significance (MGUS) is the premalignant condition of multiple myeloma. Given a lack of population-based screening for MGUS and its asymptomatic nature, the epidemiology of MGUS remains unknown. This study estimated age- and race/ethnicity-specific MGUS incidence and preclinical duration from MGUS to multiple myeloma in the United States.

Methods: A previously published modeling approach was used to calculate national MGUS incidence using estimates of MGUS prevalence, multiple myeloma incidence, multiple myeloma-specific and all-cause mortality, and population age distribution from the National Health and Nutrition Examination Survey, 1999 to 2004, and Surveillance, Epidemiology, and End Results, 2000 to 2021. The estimated MGUS prevalence was divided by MGUS incidence to obtain preclinical duration of multiple myeloma.

Results: MGUS incidence for non-Hispanic White (NHW) populations was 52, 86, 142, and 181 and for non-Hispanic Black (NHB) population was 110, 212, 392, and 570 per 100,000 person-years at ages 50, 60, 70, and 80 years, respectively. The average preclinical duration was 20.5 (95% confidence interval, CI, 16.5-26.1) years for the NHW population and 14.2 (95% CI, 11.5-17.6) years for the NHB population. The cumulative risk of developing MGUS in age 50 to 85 was 2.8% (95% CI, 1.7%-4.2%) for the NHW population and 6.1% (95% CI, 3.8%-10.0%) for the NHB population.

Conclusions: NHB populations had a higher MGUS incidence rate at all ages and a shorter preclinical duration of multiple myeloma compared to their NHW counterparts.

Impact: This study provides insights into the epidemiology of MGUS and enhances our understanding of the natural history of multiple myeloma. See related In the Spotlight, p. 1547.