Prostate cancer starts as a growth of cells in the prostate. A part of the male reproductive system, the prostate is a small walnut-shaped gland that produces the fluid that nourishes and transports sperm.

Symptoms include trouble urinating, a decreased force in the stream of urine, blood in the urine and blood in the semen. There might be no symptoms at first.

Some types of prostate cancer grow slowly and need minimal or no treatment. Other types are aggressive and require radiation, surgery, hormone therapy, or other treatments.