Prostate cancer characteristics in fathers and risk of early onset high‐risk prostate cancer in sons

A family history of prostate cancer in first-degree relatives is an established risk factor for prostate cancer, but the specific associations between prostate cancer characteristics in fathers and the risk of high-risk prostate cancer in their sons remain unclear. We identified men in Prostate Cancer data Base Sweden whose fathers had been diagnosed with prostate cancer in 1998-2005. We compared the observed number of prostate cancer diagnoses in these men with the expected number in the Swedish male population, estimating standardized incidence ratios (SIR). The median age of the 25,287 included sons of men with prostate cancer was 52 years (interquartile range 47-57 years) at end of follow-up. Their overall risk of a prostate cancer diagnosis was higher if the father had been diagnosed at less than 65 years old (SIR, 4.3, 95% confidence interval CI, 3.8-5.0), compared with having a father diagnosed when 70 years old or older (SIR, 2.3; 95% CI 1.9-2.8). Sons of fathers diagnosed at less than 65 had a higher risk of Gleason score ≥8 cancers (SIR, 2.3; 95% CI 1.1-4.1) than sons of fathers diagnosed at 70 years old or older (SIR, 1.2; 95% CI 0.4-2.6). Having a father with a Gleason ≥8 cancer was associated with an increased risk for a Gleason ≥8 cancer (SIR, 2.6; 95% CI 1.1-5.1). These population-based results suggest that the father's prostate cancer characteristics should be considered when counseling men on prostate-specific antigen testing and diagnostic strategies.