The prostate is the gland below a man's bladder that produces fluid for semen. Prostate cancer is the third most common cause of death from cancer in men of all ages. It is rare in men younger than 40.
Levels of a substance called prostate specific antigen (PSA) is often high in men with prostate cancer. However, PSA can also be high with other prostate conditions. Since the PSA test became common, most prostate cancers are found before they cause symptoms.