Assessment of prostate cancer polygenic risk score in a community-based pilot study

Background: Currently, prostate-specific antigen (PSA) testing remains the most important tool for prostate cancer (PCa) screening, yet it does not fully inform on personal risk level. Therefore, we collected information on screening behavior, family history, and polygenic risk score (PRS) from unaffected men to assess the association among PCa screening behavior, family history, and PRS. Methods: We collected past screening behavior, family history, and self-estimated risk information using a structured questionnaire, and saliva samples to generate PRS. Genotyping was conducted using the Illumina Oncoarray assay using saliva DNA. We investigated relationships among PCa screening behavior, family history, and PRS. Results: PRS information was generated from 76 unaffected men recruited from various community settings. Among 53 African American (AA) men, 13/53 (24.5%) were in the low-risk category (<30 percentile), and 17/53 (32%) were in the high-risk category (>70 percentile). In comparison, 21/23 (91%) of European American (EA) participants were in the low-risk category, and none of EA participants were in the high-risk category. AA men had a significantly higher PRS for PCa than EAs (p<0.001). Three variables (i.e., age, family history, and PRS) were significantly associated with prior PCa screening behaviors. Discussion: This study suggested differential genetic risk levels between racial groups. Men with a high risk of PCa could benefit from informed discussions around the risks and benefits of available options for PCa screening, especially among AA men. PRS information may assist AA men and clinicians in shared and informed decision-making discussions for routine PSA screening.