Combining magnetic resonance imaging with a multi-ancestry polygenic risk score to improve identification of clinically-significant prostate cancer.

Multi-parametric magnetic resonance imaging (mpMRI) has emerged as an important tool for identifying clinically-significant prostate cancer. We examined if the addition of a 400-variant multi-ancestry polygenic risk score (PRS) to mpMRI has the potential to improve identification. Based on data from 24,617 men from the Mass General Brigham Biobank, we identified 1,243 men who underwent mpMRI. Men in the top PRS quartile were more likely to have clinically-significant prostate cancer (47.1% vs 28.6% in the bottom PRS quartile, adjusted relative proportion 1.72 [95% CI 1.35-2.19]). Both among men with a positive and a negative mpMRI, men in the top PRS quartile had the highest frequency of clinically-significant cancer. In a constructed scenario for selecting men to undergo biopsy, use of the PRS lowered the frequency of missed clinically-significant cancers from 9.1% to 5.9%. Our study provides initial support for using the PRS to improve identification of potentially lethal prostate cancer.