ASPO Abstracts
Prevalence of monoclonal gammopathy of undetermined significance (MGUS) in U.S. Black women
Category: Cancer Health Disparities
Conference Year: 2022
Abstract Body:
Purpose of the study: Compared to non-Hispanic whites (NHWs), Black men and women have over a 2-fold higher incidence of multiple myeloma and a higher incidence of its asymptomatic precursor condition, monoclonal gammopathy of undetermined significance (MGUS). A previous study based in the National Health and Nutritional Examination Survey (NHANES; Landgren et al., 2014) estimated the age-adjusted prevalence of MGUS in Black individuals ages 50 and older to be 3.7% (vs. 2.3% in NHWs). We used data from a national cohort of Black women to calculate the prevalence of MGUS in this population.Methods: We screened archived serum samples collected between 2014-2017 from 1707 randomly selected participants in the Black Women's Health Study (BWHS) ages 50-79 for evidence of MGUS. Women with prior cancers were excluded. All samples underwent serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE). Results were interpreted by a single pathologist. MGUS cases were defined as presence of an M protein <3 g/dL in the serum.Results: We identified 163 cases of MGUS (crude prevalence, 9.6%). The overall age-adjusted prevalence, with direct standardization to the 2000 U.S. Census age distribution for comparison with prior literature, was 9.0% (95% confidence interval: 7.6%, 10.4%). The prevalence increased with increasing age: estimates were 5.7%, 11.0% and 12.4% among women ages 50-59, 60-69, and 70-79, respectively. IgG MGUS was observed in 116 cases (71%), IgA MGUS in 34 cases (21%) and IgM MGUS in 10 cases (6%).Conclusions: These results suggest that previously published estimates of MGUS prevalence in U.S. Black women may be underestimates. Reasons for the higher than expected prevalence are unknown, but could reflect temporal trends: the NHANES data were based on blood samples collected in the early 1990s and early 2000s, whereas samples in the Black Women's Health Study were collected from 2014-2017. Given the incurable nature of multiple myeloma, a better understanding of etiologic factors in MGUS and multiple myeloma development is urgently needed to inform opportunities for risk reduction, particularly in high-risk populations.
Keywords: MGUS, multiple myeloma, racial disparities