The aim of this trial is to determine the effectiveness of metformin hydrochloride (Fortamet) and aspirin in prostate cancer. The main outcome to be measured is the change in prostate specific antigen (PSA - protein elevated in the blood in the presence of prostate cancer) rates after 6 months. This trial is being conducted in New Jersey, in the US.

Prostate cancer is cancer that starts in the prostate gland (figure 1). The prostate gland is a small, walnut-sized structure that makes up part of a man's reproductive system by producing fluid that is part of semen. It sits below the bladder and in front of the rectum, and forms a ring around the urethra, the tube that carries urine out of the body.

Prostate cancer occurs most often in men older than 50. Although prostate cancer is very common, most men do not die from it. This is because prostate cancer usually grows very slowly.