The incidence of prostate cancer continues to increase in the US. Compared with other common cancers such as those of the breast and lung, the causes of prostate cancer remain poorly understood. Research endeavors continue to identify predictors of risk for prostate cancer, of which familial and genetic factors are among the strongest. Known risk factors can show significant heterogeneity in their association with prostate cancer development. However, the identification and further characterization of risk modifiers might provide insight into treatment and prevention of prostate cancer.