Prostate anatomy and prostate cancer screening, diagnosis, staging, and prevention

The prostate is located between the bladder and the external sphincter and normally is 4 cm in length and 4–5 cm in width. Prostate cancer is the third leading cause of cancer-related death in men. Prostate serum antigen (PSA) is used for the screening, diagnosis, treatment, and monitoring of prostate cancer. PSA screening alone has a higher detection rate than digital rectal examination alone, but detection rates are highest when the two exams are combined. The diagnosis of prostate cancer is made histologically by prostate needle biopsy in the majority of cases. The most widely accepted grading system is the Gleason grading system, which is based on the architectural pattern of the prostate glands. Based on current evidence, 5α-reductase inhibitors have been shown to reduce the relative incidence of prostate cancer compared to placebo.