Although previous research has demonstrated an increased risk of prostate cancer in those with a family history of the disease, researchers in Sweden have, for the first time, estimated the risk of developing various types of prostate cancer for men with brothers and/or fathers with the disease.1
Because familial prostate cancer risk estimates are increased by clinically insignificant low-risk cancer diagnosed after PSA testing, researchers sought to calculate age-specific probabilities of non-low–risk and high-risk prostate cancer.
For the study, investigators analyzed data from 51,897 brothers of 807 men with prostate cancer included in the Prostate Cancer data Base Sweden (PCBaSe).
Results showed that the population probability of any prostate cancer was 4.8% (95% CI, 4.8-4.9) at age 65 years and 12.9% (95% CI, 12.8-12.9) at age 75 years. The probability of non-low–risk prostate cancer was 2.8% (95% CI, 2.7-2.8) at age 65 years and 8.9% (95% CI, 8.8-8.9) at age 75 years, and of high-risk prostate cancer was 1.4% (95% CI, 1.3-1.4) at age 65 years and 5.2% (95% CI, 5.1-5.2) at age 75 years.
But for men with a brother with prostate cancer, researchers found that the probabilities of any prostate cancer were 14.9% (95% CI, 14.1-15.8) at age 65 years and 30.3% (95% CI, 29.3-31.3) at age 75 years. The probabilities of non-low–risk prostate cancer and high-risk prostate cancer were nearly 19% (95% CI, 17.9-19.6) and 8.9% (95% CI, 8.2-9.5), respectively, at age 75 years.
Of note, for men with 2 affected brothers, the probability of high-risk cancer at age 75 years was 13.6% (95% CI, 9.9-17.6), suggesting a higher risk of prostate cancer for men with a stronger family history of the disease.
“These age-specific probabilities … are more informative than relative risks of any prostate cancer and more suitable to use for counseling men with a family history of prostate cancer,” the authors conclude.
1. Bratt O, Drevin L, Akre O, Garmo H, Stattin P. Family history and probability of prostate cancer, differentiated by risk category: a nationwide population-based study. J Natl Cancer Inst. 2016 Jul 10. doi: 10.1093/jnci/djw110. [Epub ahead of print]