The prostate is a gland in the male reproductive system. It makes most of the semen that carries sperm. The walnut-sized gland is located beneath the bladder and surrounds the upper part of the urethra, the tube that carries urine from the bladder.

Prostate cancer is a major health concern for American men. The disease is rare before age 50, and experts believe that most elderly men have traces of it.

In 2014, about 233,000 new cases will be diagnosed in the U.S., and about 29,480 will die of it. African-American men are more likely to get prostate cancer and have the highest death rate. In other parts of the world -- notably Asia, Africa, and Latin America -- prostate cancer is rare.

Prostate cancer is usually a very slow growing cancer, often causing no symptoms until it is in an advanced stage. Most men with prostate cancer die of other causes, and many never know that they have the disease. But once prostate cancer begins to grow quickly or spreads outside the prostate, it is dangerous.

Prostate cancer in its early stages (when it’s only found in the prostate gland) can be treated with very good chances for survival. Fortunately, about 85% of American men with prostate cancer are diagnosed in an early stage of the disease.