The risk of developing prostate cancer increases with age. 1 in 10,000 men younger than 40 will be diagnosed with prostate cancer. But 1 in 15 men in their sixties will be diagnosed with prostate cancer. Family history. Being born with a gene mutation, is one of the unavoidable risk of prostate cancer. Two of them include the BRCA1 and the BRCA2 gene mutations. This may explain why prostate cancer runs in families. So having a father or a brother with prostate cancer may double your risk, especially if the relative was diagnosed before the age of 55. Hormones. The level of the male sex hormone called testosterone may be higher in some men than others. Higher levels of testosterone have been linked to a higher risk of prostate cancer. Men who use testosterone therapy are at higher risk of developing prostate cancer. As the increase in testosterone stimulates the growth of the prostate gland. Race. Studies show that African-American men are about 70% more likely to develop prostate cancer in their lifetime than Caucasians or Hispanic men.