P063: A second-generation polygenic risk score (PRS) based on genetic ancestry improves breast cancer (BC) risk prediction for all ancestries*

Common genetic variants, mainly single nucleotide polymorphisms (SNPs), explain substantial genetic susceptibility to BC. PRS have been developed to quantify the combined effects of BC-associated SNPs, providing important information about BC risk. Historically, however, the genome-wide association studies on which PRS are based have been conducted in predominantly European populations, resulting in PRS that are poorly calibrated and inaccurate in non-European populations.