ABSTRACT
Compared to non-Hispanic whites, African Americans have a more than 2-fold higher incidence of multiple
myeloma (MM) and its asymptomatic precursor condition, monoclonal gammopathy of undetermined
significance (MGUS). However, the etiological factors underlying these racial disparities are not known and few
epidemiologic resources are currently available to support research in diverse populations. Notably, there is
little evidence that genetic factors explain these disparities; differences in prevalence of MGUS and MM by
race may thus reflect external lifestyle and social factors. We posit that racial disparities are reflected in
socioeconomic status (SES) and geospatial factors such as the “health” of the environment in which one lives
(termed “built environment”), both of which are known to be linked to race and a variety of health outcomes.
The Black Women's Health Study (BWHS) and the California Teachers Study (CTS), well-established
complementary cohorts of women, provide a unique opportunity to study SES and built environment factors for
MGUS in African American and non-Hispanic white women with up to 25 years of individual-level risk factor
information, assessed through repeated health questionnaires, available as well as geocoded residential
addresses. We propose an epidemiologic study pooling data from these two cohorts to evaluate the role of
individual and neighborhood SES and the built environment in racial disparities in MGUS. Prevalent cases of
MGUS will be identified by screening 8,000 cohort participants (3,300 in BWHS and 4,700 in CTS) with
archived blood specimens using gold-standard laboratory assays for the diagnosis of MGUS; we expect to
identify 660 cases of MGUS (including 330 African American and 330 non-Hispanic white women). We
hypothesize that neighborhood disadvantage and attributes of the built environment that inhibit healthy
behaviors increase risk and contribute to known racial disparities in MGUS. We will determine associations of
neighborhood deprivation and markers of individual SES, such as educational achievement, parental education
level, income, and early life financial instability, in relation to MGUS overall and by race. We will also explore
how characteristics of the built environment, such as urbanicity and neighborhood walkability, and the cross-
classification of these variables with SES, are associated with MGUS and may explain observed differences in
prevalence by race. Our proposed study is particularly innovative because it moves beyond the traditional,
single-level predictor model to an approach that addresses the complexity of both individual- and contextual-
level predictors for disease. The wide geographic/rural-urban, racial, and socioeconomic diversity of our study
population across cohorts makes it an ideal setting in which to interrogate the intersection between race, SES,
and neighborhood attributes on MGUS and MM risk. This research therefore has great potential to advance
current knowledge about MGUS etiology, to inform opportunities for risk reduction in high-risk understudied
populations, and to close the gap in racial disparities in multiple myeloma and its precursor conditions.