Prostate cancer is the most common malignant tumor of the male reproductive system. Usually, what we call prostate cancer refers to prostate adenocarcinoma, which is a malignant tumor that occurs in the prostate epithelium. The causes of prostate cancer are complex and may be related to the following factors: 1) genetic factors: the prevalence rate of people with family history of prostate cancer is 8 times higher than the general population; 2) regional differences: the prevalence rate is higher in Europe and America and lower in Asia; 3) excessive sexual life; 4) high-fat diet; 5) environmental factors.