Avodart, a popular drug used to treat an enlarged prostate gland could have an additional benefit. Research shows it helps slow the progression of early-stage prostate cancer, thus reducing the need for aggressive treatment in some men.

Avodart belongs to a class of drugs called 5-alpha reductase inhibitors, which work by interfering with the effects of certain male hormones on the prostate. And in a three-year study published online Jan. 25 in The Lancet, prostate cancer progressed in 38 percent of 144 men with early prostate cancer who were treated with Avodart, compared with 48 percent of the 145 men who received a placebo.

Prostate cancer can grow and spread slowly, which is why some men are urged to engage in so-called watchful waiting when the cancer is first diagnosed. The researchers noted Avodart may help such men feel comfortable with surveillance as opposed to radical treatment.

“The concept of active surveillance is gaining traction in most parts of the world,” said study author Dr. Neil E. Fleshner, head of the division of urology at the Princess Margaret Hospital in Toronto. Still, some men are uncomfortable with doing nothing in the face of a cancer diagnosis, he said. “By using this drug, we can improve the proportion of men who remain committed to the surveillance.”

And while the medication does have side effects including reversible breast enlargement and tenderness and some sexual dysfunction, Dr. Louis Potters, chairman of radiation medicine at North Shore University Hospital and Long Island Jewish Medical Center in Manhasset, N.Y. said, “In the U.S., patients have a tendency to hear the word ‘cancer,’ and want to treat it right away. In these men with early prostate cancer, we can now say, ‘Let’s put you on this medication, and see what happens over the next couple of months.’”

Positive effects aside, the U.S. Food and Drug Administration recently issued a warning that men who take 5-alpha reductase inhibitors like Avodart may have an increased risk for high-grade prostate cancer — leading Dr. Ryan Terlecki, an assistant professor of urology at Wake Forest Baptist Medical Center in Winston-Salem, N.C., to say he believes the overall role these medications play for urologists will decrease.