The prostate gland, a male sex organ, produces a thick fluid that makes up most of the
semen. It is located between the bladder and rectum. A normal sized prostate is about
the size of a walnut. The urethra, a tube that drains the urine from the bladder during
urination, passes through the prostate.
Interference with urinary flow is usually caused by a non-malignant enlargement of the
prostate called benign prostatic hyperplasia (BPH). Symptoms associated with BPH
include frequency of urination, inability to completely empty the bladder, a weak urinary
stream and frequent urination during the night. Infrequently, prostate cancer can cause
similar symptoms. Diabetes and other medical conditions, and some medications can
also cause some of these symptoms.
The prostate, like all other organs of the body, is made up of many types of cells.
Normally, cells divide in an orderly and controlled fashion to produce more cells only
when they are needed. This process helps to keep the body healthy. Cancer is a group
of diseases that have one thing in common: cells become abnormal and then begin to
divide and grow uncontrollably. When this happens a malignant lump or tumor may
appear. In the case of prostate cancer, sometimes a nodule or firm area can be felt on
digital rectal exam (DRE).
Cancer cells may invade and damage the healthy surrounding tissue. In the case of
prostate cancer, the adjacent normal tissues most commonly involved with cancer include
the surrounding fat and muscle, the nerves that stimulate an erection (located in the
neuro-vascular bundle), the seminal vesicles, (sacs that sit on top of the prostate that store
the seminal fluid that is ejaculated during sex), the bladder and the urethra. Cancer cells
can also grow into the blood stream or into lymphatic channels and spread to other parts
of the body. This process is called metastasis. When prostate cancer metastasizes, it
most commonly spreads to the pelvic lymph nodes and the bones.
