Enlarged Prostate Drug Slows Early Cancer

Avodart slows prostate cancer in study

(RxWiki News) You've probably seen TV commercials for this medication. Avodart (dutasteride) is approved by the U.S. Food & Drug Administration (FDA) to treat enlarged prostate, a condition that can keep men busy with frequent trips to the restroom.

New research shows this drug may have additional benefits.

Avodart may slow the growth of early-stage prostate cancer, which could reduce the need for treatments that can have devastating side effects that interfere with sexual and urinary function.

"Ask your doctor if Avodart is appropriate to treat your prostate cancer."

The study was conducted at Princess Margaret Hospital in Toronto, Canada and led by Neil E. Fleshner, M.D., FRCSC, MPH, an oncologist who specializes in prostate and bladder cancers.

This study called "Reduction by Dutasteride of Clinical Progression Events in Expectant Management" (REDEEM) involved 302 men between the ages 48 to 82 years old.

The men all had low-risk localized prostate cancer and were undergoing active surveillance, meaning they were being closely followed  to carefully monitor cancer growth. 

The men were randomly assigned to  receive either 0.5 mg of Avodart once a day or a placebo for three years. Participants had biopsies at 18 months and three years to measure disease progression. Anxiety relating to the cancer  was assessed with a questionnaire. 

The study found that Avodart was effective in significantly delaying the progression of prostate cancer.  Of men who received the drug, 38 percent saw the disease worsen, compared to 48 percent of those who were given a placebo.

Men who received the drug were less likely to have cancers detected in the final biopsy - 36 percent, compared to 23 percent who received a placebo. The treated men also reported they had significantly less anxiety relating to the cancer. 

Those who took Avodart did experience more drug-related side effects than those who weren't treated (24% vs 15%). These were side effects commonly experienced with the drug - sexual problems and breast tenderness or enlargement. compared with those given placebo.

There were no deaths related to prostate cancer and the disease did not spread in any of the men participating in the study. 

"Our trial is the first study to show the benefits of use of a 5α-reductase inhibitor to reduce the need for aggressive treatment in men undergoing active surveillance for low-risk prostate cancer…delaying their time to pathological progression and initiation of primary therapy", said Dr. Fleshner.

About 20 percent of men in the United States will be diagnosed with prostate cancer. When the disease is confined to the prostate, small in size and designated as low-risk, treatment is often not needed. Instead they can choose active surveillance which involves regular assessment and biopsies, as necessary, to track disease progression. 

Avodart is approved to treat benign prostatic hyperplasia, or BPH. It in a class of drugs known as 5-alpha reductase inhibitor (5-ARI) and works by blocking a natural substance that enlarges the prostate. This results in the prostate shrinking which in turn, relieves symptoms of BPH - frequent and difficult urination, and decreases the chance that surgery will be needed to treat this condition.

Without insurance, Avodart costs about $130 for 30 tablets.

In June, 2011, the FDA sent warning letters to healthcare professionals about an increased risk of men using 5-ARI drugs - including Avodart - developing a serious form of prostate cancer. This warning was based on two large trials.

The FDA recommend that these drugs not be prescribed before screening the men for prostate cancer.

The authors of the REDEEM study conclude: "The benefit of dutasteride is to reduce the amount of low-grade cancer, not to reduce the risk of being diagnosed with higher-grade cancer. This reduction leads to fewer men with biopsy-detectable prostate cancer, and therefore fewer treatment interventions. Dutasteride…provides a treatment option for men with low-risk, localised disease."

This research appeared in an article published Online First January 23, 2011 in the Lancet.

Review Date: 
January 23, 2012