Biological determinants of health disparities in multiple myeloma

Abstract

Multiple myeloma is a rare plasma cell cancer, and incidence rates among patients of African descent are about twice those among patients of European descent. Rates of multiple myeloma vary among different populations, but the reasons for the racial disparities in multiple myeloma are largely unknown. Epidemiology has identified risk factors for multiple myeloma including race, advanced age, gender, family history, and exposure to different genetic toxins including radiation. Race and ancestry play a large role in predicting the risk for multiple myeloma, yet there exists a paucity of literature that explores the molecular contribution of race and ancestry to disease. In this review, we describe the relevant literature that describes the observed racial differences according to distinct tumor immunobiological and ancestral differences in populations.

Fig. 1. Prevalence of monoclonal gammopathy of undetermined significance (MGUS) in the among residents of Olmsted County, Minnesota compared to persons from the National Health and Nutritional Examination Survey (NHANES).

Data has been re-plotted from original publications. Olmsted County, MN study (n = 21 462 persons). See reference for Olmsted County, MN prevalence percentages. NHANES study (n = 12 482 persons; n = 2331 non-Hispanic blacks [black or African American], n = 2475 Mexican Amersicans, n = 7051 non-Hispanic whites [white], and n = 625 “others”). See ref. for NHANES prevalence percentages. Age-adjusted prevalence rates are comparable between studies as the prevalence rates have been similarly standardized to the 2000 US population. Data represents patients over 50 years of age and includes the sexes men and women. AA, African American; WH, Whites. *NHANES age-adjusted prevalence rate contains information from Mexican Americans, whites, and African Americans. However, rates are similar among Mexican Americans and whites. MGUS estimation from the NHANES study likely reflects the true estimate as it is the most representative cohort of the United States population

Fig. 2. The Yin and Yang of mortality and survival in multiple myeloma.

a, b, c Age-adjusted rates of multiple myeloma incidence (a), mortality (b), and 5-year survival percentae (c) in all races (red, diamond), blacks (green, circle), and whites (blue, square) from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute (NCI) between 1975 and 2014. Despite the 2–3 times higher incidence and mortality observed among blacks with multiple myeloma, the 5-year survival for blacks is equal to superior to whites given the year