Abstract 2552: A genome-wide association study of prostate cancer in West African men.

Age-adjusted mortality rates for prostate cancer are higher for Africa compared with North America or Western Europe. In addition, African American men are noted to have higher age-adjusted incidence rates of this malignancy than European American men. Coupled with the fact that West Africa is the principal ancestral region of African-American men has led to the hypothesis that there may exist distinct ancestral genetic profiles which mediate prostate cancer risk. In addition, advantages of conducting a genome-wide association study (GWAS) of prostate cancer in African men include a more discrete linkage disequilibrium (LD) structure, a higher number of private single nucleotide polymorphisms (SNPs), the predominance of symptomatic disease, and assessment of unique exposures. The Ghana Prostate Study was conducted collaboratively involving the US National Cancer Institute (NCI) and the University of Ghana during 2006-2012. The NCI Cancer Genomics Research Laboratory genotyped 494 prostate cancer cases and 498 population controls using the Illumina HumanOmni5-Quad BeadChip. Associations were assessed using multivariate logistic regression adjusted for age and genetic ancestry. We sought to validate the 30 most promising SNP associations with prostate cancer through the African American Prostate Cancer GWAS Consortium. A novel locus at 10p14 for prostate cancer risk was the strongest signal detected, and the 8 SNPs at this locus were in LD. This locus is located 360 kb 5’ of GATA3 and the 8 SNPs reside within an intron of LincRNA gene RP11-543F8.2. Analysis of African 1000 Genomes Project data did not indicate LD between 10p14 SNPs and splice or exonic SNPs of this gene, while HaploReg found no significant enrichment of enhancer elements. None of the most promising 30 SNPs replicated in the African American Prostate Cancer GWAS Consortium. This may be due to chance or differences in population genetics, environment, and/or proportion of symptomatic disease. Further genetic studies of prostate cancer in African men are needed to validate the 10p14 susceptibility locus. Citation Format: Michael B. Cook, Zhaoming Wang, Edward D. Yeboah, Andrew A. Adjei, Yao Tettey, Richard B. Biritwum, Evelyn Tay, Ann Truelove, Shelley Niwa, Lisa Chu, Meredith Yeager, Amy Hutchinson, Kai Yu, Christopher A. Haiman, African American Prostate Cancer GWAS Consortium, Robert N. Hoover, Ann Hsing, Stephen J. Chanock. A genome-wide association study of prostate cancer in West African men. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2552. doi:10.1158/1538-7445.AM2013-2552