Abstract 1311: Germline variation at 8q24 and prostate cancer risk

Abstract

Abstract The 8q24 region harbors multiple risk variants for distinct cancers including 7 for prostate cancer, the majority of which lie in separate linkage disequilbrium blocks. It is not known whether a common biological mechanism underlies the association of genetic variation with cancer risk at 8q24, or whether there are site-specific functions of regulatory elements that are affected in this region. Given the proximity, the MYC oncogene is a likely candidate as are multiple long non-coding RNAs in the region. To further understand the contribution of germline variation to prostate cancer risk we performed a comprehensive fine-mapping analysis of the region in men of European ancestry from the PRACTICAL/ELLIPSE Consortium. More specifically, we tested 1,731 genotype tag SNPs and 12,221 imputed variants spanning the risk region (127.3-129.0Mb) in 56,363 prostate cancer cases and 37,386 controls of European ancestry that were genotyped with the Illumina OncoArray. We performed stepwise logistic regression and identified 13 variants with risk allele frequencies between 0.006 and 0.998 that surpassed genome-wide statistical significance (p-values between 3.2x10-8 and 8.0 x10-78) and with per allele odds ratios ranging from 1.11(rs5013678) to 2.68(rs183373024). Ongoing analyses that will be presented include incorporating existing GWAS and fine-mapping data (iCOGs) for men of European and African ancestry (35,000 cases and 35,000 controls) using JAM, a Bayesian approach that investigates multi-SNP models using marginal meta-analysis statistics. Leveraging the power from the overall multiethnic meta-analysis (>93,000 cases and >72,000 controls) will provide further insight into the number of independent signals in the region and their contribution to prostate cancer risk in these populations. Citation Format: Kan Wang, Ali Amin Al Olama, Rosalind Eeles, David Conti, Zsofia Kote-Jarai, Christopher A. Haiman. Germline variation at 8q24 and prostate cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1311. doi:10.1158/1538-7445.AM2017-1311