Abstract 1328: Evaluation of common genetic variants in 15 colorectal cancer susceptibility loci among African Americans .

Abstract

Abstract Background: Genome-wide association studies (GWAS) conducted primarily in populations of European ancestry, have identified multiple single-nucleotide polymorphisms (SNPs) at 15 loci associated with colorectal cancer (CRC) risk. Limited studies have been conducted to evaluate the association of these SNPs with colorectal neoplasia risk in African Americans. Methods: We analyzed 19 SNPs within 15 CRC loci in African Americans recruited from two studies, including 206 CRC cases and 1,000 controls from the Southern Community Cohort Study (SCCS), and 203 colorectal adenoma cases and 461 controls from the Tennessee Colorectal Polyp Study (TCPS). Logistic regressions were used to derive adjusted odds ratios and their 95% confidence intervals for the associations between SNPs and disease risk. We also performed a meta-analysis including 1,586 cases and 2,956 controls regarding the association of 11 SNPs with colorectal neoplasia risk in African Americans. Results: In the combined analysis of data from the SCCS and TCPS, we found two SNPs (rs10505477 and rs6983267) at 8q24 to be significantly associated with colorectal neoplasia risk (P < 0.05). Two additional SNPs, rs7758229 (SLC22A3) and rs4444235 (14q22), showed marginally significant associations with colorectal neoplasia (P < 0.10). In the meta-analysis including data from this study and two other studies, rs16892766 (8q23), rs6983267 (8q24), and rs7014346 (8q24) were significantly associated with colorectal neoplasia with no evidence of heterogeneity across studies. Conclusions: Genetic variants at 8q23 and 8q24 identified in GWAS conducted in European descendants may also be associated with colorectal neoplasia risk in African Americans. Impact: Findings from this study may be helpful for future studies to fine-map GWAS-identified loci to identify causal variants for CRC. Citation Format: Ben Zhang, Qiuyin Cai, Jirong Long, Guoliang Li, Lisa B. Signorello, Martha J. Shrubsole, William J. Blot, Wei Zheng. Evaluation of common genetic variants in 15 colorectal cancer susceptibility loci among African Americans . [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 1328. doi:10.1158/1538-7445.AM2013-1328