Abstract
Objectives: Prostate-specific-antigen (PSA) screening resulted in reduced prostate cancer (PCa) mortality in a large clinical trial, but due to many false positives and overdiagnosis of indolent disease, many guidelines do not endorse universal screening and instead recommend an individualized decision based on each patient’s risk. We sought to develop and validate a genetic tool to predict age of aggressive PCa onset and to guide decisions of whom to screen and at what age. Design: Genotype, PCa status, and age were analyzed to select single-nucleotide polymorphisms (SNPs) associated with PCa diagnosis. These SNPs were incorporated into a survival analysis to estimate their effects on age at diagnosis of aggressive PCa (i.e., not eligible for surveillance per NCCN Guidelines; any of: Gleason score ≥7, stage T3-T4, PSA ≥10, nodal metastasis, distant metastasis). The resulting polygenic hazard score (PHS) is an assessment of individual genetic risk. The final model was applied to an independent dataset containing genotype and screening PSA data. PHS was calculated for these men to test prediction of PCa-free survival. Setting: Multiple, international PRACTICAL consortium member institutions. Participants: All PRACTICAL consortium participants of European ancestry with known age, PCa status, and quality-assured iCOGS array genotype data. Development dataset comprised 31,747 men. Validation dataset comprised 6,411 men. Main outcome measures: PHS prediction of age of onset of aggressive PCa in validation set. Results: In the independent validation set, PHS calculated from 54 SNPs was a highly significant predictor of age at diagnosis of aggressive PCa (z=11.2, p<10-16). When men in the validation set with high PHS (>98th percentile) were compared to those with average PHS (30th-70th percentile), the hazard ratio for aggressive PCa was 2.9. Conclusions:Polygenic hazard scores give personalized genetic risk estimates that predict for age of onset of aggressive PCa.