Like other cancers, prostate cancer is a disease of cells growing out of control. Spurred by changes in the genes, the glandular cells of the prostate multiply abnormally. These cancer cells may cross tissue barriers and may then spread throughout the body. Most cancers are named after the part of the body where the cancer first starts.
Prostate cancer starts in the prostate gland.
It is just below the bladder and in front of the rectum. The urethra, the tube that carries urine, runs through the prostate. The prostate normally starts out about the size of a walnut. The prostate gland makes a fluid that is part of semen, the fluid that contains sperm. Nerves found next to the prostate take part in causing an erection of the penis, and treatments that remove or damage these nerves can cause impotence, or problems with erections.