Current diagnostic modalities are inadequate to reliably differentiate between aggressive and indolent forms of prostate cancer (PCa). A significant number of men receive potentially unnecessary treatment along with associated morbidities. Identification of novel risk factors will allow for more reliable early diagnosis of PCa. Defective sensors of DNA damage and the resulting genetic instability likely are involved in the early development of PCa. The objective of this project is to determine if DNA damage and genetic instability are harbingers of PCa using prostate biopsy samples from men at high risk for this disease.