The study involved 8,200 men ages 50 to 75 with high PSA blood test scores but no sign of cancer on biopsy. They were given Avodart, generically known as dutasteride, or dummy pills and new biopsies two and four years later.

 

The study showed that after two years, prostate cancer was found in 17 percent of men on dummy pills and 13 percent of those on the drug. After four years, it was found in another 12 percent of men on the placebo and 9 percent on dutasteride.

 

“We think this is very good news,” said Gerald L. Andriole, chief of urologic surgery at Washington University in St. Louis, who led the study.

 

He added that Avodart may work against cancer by reducing the size of tumors or slowing their growth. The findings are of great importance as at the moment there are no drugs approved to reduce risk of prostate cancer in men with heightened risk of the disease.

 

The drug is currently approved for the treatment of benign prostate enlargement. It had sales of $581 million in 2008, according to the most recent data.