Prostate genetic score (PGS‐33) is independently associated with risk of prostate cancer in the PLCO trial

Background To investigate the ability of the prostate genetic score (PGS‐33), a germ‐line biomarker of prostate cancer (PCa) risk, to categorize men participating in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Methods We obtained the genetic data from the Cancer Genetic Markers of Susceptibility (CGEMS), a nested case control study examining germ‐line DNA in the screened arm of the PLCO trial. A PGS‐33 was calculated based on their genotype at 33 PCa associated single nucleotide polymorphisms (SNPs). The primary outcome was the diagnosis of PCa and primary predictor was PGS‐33. Results We identified 2,244 subjects (no cancer, N = 1017) and cases (N = 1227). The PGS‐33 ( P <0.001), prostate specific antigen (PSA; P < 0.001), family history of PCa (< 0.001), abnormal digital rectal exam (DRE, P < 0.001), and history of ever smoking ( P  = 0.037) were associated with a PCa diagnosis. In multivariable analysis, the log (PGS‐33) was associated with PCa diagnosis with an odds ratio of 1.68 (95% CI 1.36–2.08, P < 0.001), log (PSA) (OR 8.2; 95% CI 6.75–10.04, P < 0.001), and family history of PCa (OR 2.01; 95% CI 1.26–3.20, P  = 0.003). PGS‐33 quartiles noted an increasing rate of PCa detection in addition to PSA: 43.2% (Q1), 47.8% (Q2), 58.8% (Q3), and 69.4 (Q4) ( P < 0.001) and improvement in PSA performance ( P < 0.001). Conclusions Germ‐line DNA in the form of the PGS‐33 is able to risk stratify men regarding their risk of PCa. The PGS‐33 may have implications regarding who may benefit most from PCa screening and possibly add to PSA performance. Prostate 75:1322–1328, 2015 . © 2015 Wiley Periodicals, Inc.