The prostate is about the size of a walnut and, when the man is standing, is located in front of the rectum, behind the base of the penis, and under the bladder. It is a gland found only in men and produces some of the seminal fluid, which protects and nourishes sperm cells. The prostate surrounds the upper part of the urethra, the tube that carries urine and semen out of the penis.
Prostate cancer develops from cells of the prostate gland.
Eventually the cancer cells can spread outside the gland to other parts of the body. Prostate cancer may spread directly to tissues and organs near the prostate gland. Nerves located next to the prostate gland take part in causing an erection of the penis. Treatments that remove or damage these nerves can cause erectile dysfunction, also known as impotence. Lymph is a clear fluid that contains tissue waste products and immune system cells.