The study was one of the largest of it's kind, performed on almost 19,000 men over the course of 7. The men were randomly assigned either a placebo or the popular drug known as finasteride, which is branded as Propecia for treating baldness and is also used to treat enlarged prostate glands in older men.

After 7 years, the men taking finasteride showed a 25% lower risk of developing prostate tumors than the placebo group. However, the researchers were at first concerned about an actual higher incidence of aggressive prostate cancers in the men taking finasteride; their overall risk was lowered, but if they did develop prostate cancer it tended to be more dangerous.

A new evaluation of that study seems to have reconciled this strange finding. Since finasteride actually shrinks the prostate gland, if cancer does appear it is easier to find and thus, in the original study seemed to show an increase in tumors in some men.

Finasteride works by decreasing the amount of available dihydrotestosterone produced by the body, a male hormone. It has been known for some time that male hormones act to "feed" prostate cancer growth, and turning down this mechanism can be an effective treatment to help "starve" the cancer.

Its side effects include some of the more common ones among prostate cancer treatments: impotence, and decreased libido. Sometimes male breasts can also form, however, most side effects will reverse once treatment is stopped.

The new research concludes that finasteride is indeed an excellent treatment for those with a high risk of acquiring prostate cancer. Men who are in a high risk category for prostate cancer include those over the age of 50 and those with a close relative with prostate cancer.

Men who are interested in finasteride therapy should take up their concerns with their doctor, who will make a personalized decision based on their risk factors. This treatment may help avoid such complications as impotence and urinary incontinence, two of the most common side effects of later treatments such as surgery and radiation therapy.

This may be a blessing for those at high risk, as the quality of life concerns from treatment may actually affect men more than the cancer itself.