Abstract B126: Disparities in cancer incidence among African American and non-Hispanic White participants in the Agricultural Health Study
Authors: Ezennia Somayina C. , Parks Christine G. , Beane-Freeman Laura E. , Taylor Anne , Andreotti Gabriella , Koutros Stella , Sandler Dale P. , Hofmann Jonathan N. 
Published: December 2023

Disparities in the incidence of some cancers (e.g., prostate cancer, multiple myeloma) between African American (AA) and non-Hispanic white (NHW) individuals are well established in the U.S. overall; however, to our knowledge, no previous studies have compared cancer incidence in AA and NHW farming populations. Farmers and their families can face a variety of occupational and environmental exposures that may influence cancer risk, including pesticides, zoonotic diseases, diesel exhaust and air pollution. Given the exposures unique to farming as well as historic discrimination faced by AA farmers, we considered the possibility that racial disparities in cancer incidence might be greater in farmers than in the general population. To explore cancer disparities in farming populations, we conducted an investigation within the Agricultural Health Study (AHS), a prospective cohort of pesticide applicators (mainly malefarmers) and their spouses. Our analyses included 1,505 AA and 27,052 non-Hispanic white (NHW) farmers and spouses from North Carolina who were enrolled in 1993-1997 and followed for cancer incidence through 2014. We examined cancer incidence in AA compared to NHWparticipants, both overall and for specific sites, by estimating hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards regression models with age as the underlying time metric and adjustment for sex (in analyses of cancer sites that included both sexes) and region (coastal plains, piedmont, and mountains). We identified a total of 4,689 incident cancer cases during follow-up (335 in AA participants and 4,354 in NHW participants). Compared with NHW participants, we observed a higher incidence among AA participants for all cancers (HR = 1.36, 95% CI 1.21 – 1.52) that was apparent among men (n = 272 AA cases; HR 1.45, 95% CI 1.28-1.64) but not among women (n = 63 AA cases; HR 1.12, 95% CI 0.87-1.45). AA participants had a higher incidence of cancers of the prostate (overall: HR 2.01, 95% CI 1.67–2.43; aggressive disease: HR 2.12, 95% CI 1.62–2.79), colon and rectum (HR 1.60, 95% CI 1.15–2.23), larynx (HR 3.52, 95% CI 1.41–8.79), and multiple myeloma (HR = 2.82, 95% CI 1.43 – 5.60). We also observed non-statistically significantly elevated HRs for cancers of the lung, pancreas, kidney, and stomach among AA participants. Findings were similar after excluding participants from the mountain region where few AA participants were enrolled. The observed excesses of cancer incidence overall and for specific cancer sites among AA farmers and spouses compared to their NHW counterparts were generally more apparent than those seen in the overall U.S. population; we plan to further evaluate these disparities through comparisons with statewide cancer incidence rates in North Carolina. Additional efforts are also needed to better understand factors contributing to these disparities, which can inform ways to promote the overall health and well-being of AA farmers and ensure that resources are allocated equitably across all populations.

Citation Format: Somayina C. Ezennia, Christine G. Parks, Laura E. Beane-Freeman, Anne Taylor, Gabriella Andreotti, Stella Koutros, Dale P. Sandler, Jonathan N. Hofmann. Disparities in cancer incidence among African American and non-Hispanic White participants in the Agricultural Health Study [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B126.