Abstract PO-199: Determining the association between circulating fatty acids, immune oncological markers, and prostate cancer risk in a diverse cohort
Authors: Lord Brittany D. , Minas Tsion , Dorsey Tiffany H. , Baker Francine , Tang Wei , Yeboah Edward D. , Tettey Yao , Biritwum Richard B. , Adjei Andrew A. , Tay Evelyn , Mensah James E. , Hoover Robert N. , Hsing Ann W. , Cook Michael B. , Ambs Stefan 
Published: January 2022

Abstract
Men of African descent, including African American (AA) men and Ghanaian (AFR) men, have a disproportionately higher burden of lethal prostate cancer (PCa) when compared to European American (EA) men. This increased mortality burden could be partially attributed to lifestyle factors including the intake of dietary fatty acids and their metabolism, but may also relate to differences in inflammation and immune function. Although the extent to which fatty acids are PCa risk factors remains controversial, the relationship between fatty acids, inflammation and immune function, and PCa in men of African descent remains largely unexplored. Therefore, the goal of our study was to characterize the relationship between circulating fatty acids, immune-oncological mediators, and PCa in the ethnically diverse NCI-Maryland and NCI-Ghana Prostate Cancer Case-Control studies, with an over-representation of men of African descent. A CLIA-certified, mass spectrometry-based assay was applied to measure 24 fatty acids in sera from 1,562 cases and 1,693 controls. Logistic regression analyses were performed on seven types of fatty acids including total, saturated, trans, cis-monounsaturated, omega-6, omega-3 fatty acids, and the omega 6:3 fatty acid ratio to explore disease associations by population group. Additionally, we measured 82 immune-oncological proteins in the same sera and explored their role as potential mediators of the relationship between fatty acids and PCa. Using this approach, we observed a significant association between trans fatty acid levels and the odds of developing PCa in all three racial/ethnic groups. Although AFR men were found to have the lowest level of trans fatty acids compared to AA and EA men, they still experienced significantly increased odds of developing PCa with increasing trans fatty acid levels. Exploratory mediation analyses found a relationship between Palmitelaidic trans fatty acid levels and two circulating proteins, CD27 and CXCL1, with protein levels being higher in men with elevated levels of circulating Palmitelaidic trans fatty acids and an increased risk of PCa. Our findings point to a previously unexplored oncogenic role of fatty acids and immune-oncological mediators in men of African descent with PCa.
Citation Format: Brittany D. Lord, Tsion Minas, Tiffany H. Dorsey, Francine Baker, Wei Tang, Edward D. Yeboah, Yao Tettey, Richard B. Biritwum, Andrew A. Adjei, Evelyn Tay, James E. Mensah, Robert N. Hoover, Ann W. Hsing, Michael B. Cook, Stefan Ambs. Determining the association between circulating fatty acids, immune oncological markers, and prostate cancer risk in a diverse cohort [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-199.