Abstract 2969: Genetically predicted blood protein biomarkers and prostate cancer risk: an analysis in over 140,000 European descendants

Prostate cancer (PrCa) is the second most frequently diagnosed malignancy among males in many countries. Several protein markers measured in blood have been found to be associated with PrCa risk. However, most previous studies assessed only a small number of biomarkers or included a small sample size. To search for novel protein biomarkers for PrCa risk, we performed a large study in 79,194 prostate cancer cases and 61,112 controls of European ancestry included in PRACTICAL/ELLIPSE consortia by using genetic instruments. Protein quantitative trait loci (pQTLs) for 1,478 plasma proteins identified in a large study of 3,301 European descendants were used as instruments to evaluate associations between genetically predicted protein levels and PrCa risk. For proteins showing a significant association with PrCa risk, we further evaluated whether genetically predicted mRNA expression levels of the corresponding genes were associated with PrCa risk, by using mRNA expression prediction models for blood, prostate and cross tissue built using data of the Genotype-Tissue Expression Project. We identified 31 proteins showing an association of their predicted levels with PrCa risk at a false discovery rate Our study has identified multiple proteins significantly associated with PrCa risk. Further research is needed to evaluate potential utility of the identified proteins in early detection of PrCa. Citation Format: Lang Wu, Xiang Shu, Jiandong Bao, Xingyi Guo, the PRACTICAL, CRUK, BPC3, CAPS, PEGASUS consortia, Zsofia Kote-Jarai, Christopher A. Haiman, Rosalind A. Eeles, Wei Zheng. Genetically predicted blood protein biomarkers and prostate cancer risk: an analysis in over 140,000 European descendants [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2969.