Cancer mortality among US blacks: Variability between African Americans, Afro-Caribbeans, and Africans

Aggregation of all Black populations in US cancer mortality profiles masks remarkable heterogeneity by place of birth. Comparing U.S-born African Americans with African and Afro-Caribbean immigrants may highlight specific cancer prevention and control needs and clarify global cancer epidemiology. Such a comparison has yet to be undertaken on a population basis.

Using 2012-2017 vital statistics data from California, Florida, Minnesota and New York, age-standardized cancer mortality rates were computed for distinct Black populations. Comparisons were made to the majority White population using mortality rate ratios (MRR) obtained from negative binomial regression.

Of the 83,460 cancer deaths analyzed among Blacks, nearly 20 % were immigrants. African males and females had the lowest all-sites-combined cancer mortality rates (121 and 99 per 100,000, respectively), African Americans had the highest (232 and 163), while Afro-Caribbean were in between (140 and 106 respectively). The average Black:White MRR was significant for prostate (2.11), endometrial (2.05), stomach (2.02), multiple myeloma (1.87), premenopausal breast (1.66), liver (1.58) and cervical (1.56) cancers, (P < 0.05).

While, in aggregate, Blacks in the US have high cancer mortality rates, race itself is not the primary determinant of these disparities. Black immigrant populations show lower cancer mortality than both African Americans and Whites, especially for cancers where environmental factors feature more predominantly: lung, colorectal and breast. Even for cancers with high mortality among all African-descent groups, this study suggests a complex interplay between genetic and environmental factors. Endometrial cancer was unique; mortality rates were similarly high for all three analyzed Black groups.