A drug commonly prescribed to treat benign prostatic hyperplasia (BPH) has been shown to significantly cut the risk of developing prostate cancer in men with an increased risk of the disease. In an international trial involving 8,200 men, dutasteride (Avodart) reduced the chances of being diagnosed with prostate cancer by 23% after four years of use.
Trial participants were 50 to 75 years old and had elevated prostate-specific antigen (PSA) levels at the start of the trial (2.5 to 10 ng/ml). But biopsies performed within six months of the trial’s start found no evidence of the disease.
Once enrolled in the trial, the men were randomly assigned to take either dutasteride or a placebo. After two years, prostate biopsies found cancer in 17.2% of the men taking the placebo and 13.4% of those taking the drug. After four years, prostate biopsies led to a cancer diagnosis in another 11.8% of the men who received the placebo and 9.1% of those on dutasteride.
The rate of aggressive, high-grade tumors (those with a Gleason score of 7 to 10) in each group was about the same — just under 7% — allowing researchers to breathe a sigh of relief. In earlier studies, a related BPH drug, finasteride (Proscar), initially seemed to increase the risk of aggressive tumors. Subsequent analysis, however, suggested that this wasn’t true. Rather, the tumors were just easier to find in men who took the drug because it reduces the size of the prostate, meaning that the tumors were more likely to be found on a biopsy.
“Dutasteride has the potential to offer many thousands of men a way to reduce their risk of being diagnosed with prostate cancer and, as a result, more men could avoid treatment for prostate cancer and the cost and unwanted side effects associated with treatment,” said Dr. Gerald Andriole.* Andriole, the trial’s principal investigator, presented the findings at the American Urological Association’s annual meeting in April 2009.
|*Editor’s note: Dr. Andriole has received consulting fees from the drug’s manufacturer, which sponsored the trial.|
Originally published September 2009; last edited April 7, 2011.