Located in the lower pelvis, just below the bladder, the prostate surrounds the urethra, producing the fluid component of semen and helping control the flow of urine. These proteins are good indicators for the level of activity of the gland. For this reason, blood levels of PSA are closely monitored when a man has a prostate disease. Enlargement of the prostate is common with age. BPH may require medical intervention or may remain untreated and not affect the man's quality of life.
Prostate cancer can also form in the tissue of the central zone.
BPH most often occurs in the transition zone, which surrounds the urethra. Surrounding the prostate is the prostate capsule, a tissue that separates the prostate from the rest of the body. When prostate cancer remains inside the prostate capsule, it is considered localized and treatable with surgery. Once the cancer punctures the capsule and spreads outside, treatment options are more limited. All male mammals have a prostate, but only humans and dogs are known to develop prostate cancer.