Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=199031
Story Retrieval Date: 5/23/2013 3:21:12 AM CST
Courtesy of the National Cancer Institute
Use of dutasteride coupled with aggressive surveillance shrinks the prostate, which helps regulate the release of seminal fluid, and may be a better treatment option for men with low-risk prostate cancer, a study said.
Drug may slow or eliminate advancing prostate cancer
Doctors have traditionally pounced on prostate cancer with aggressive approaches such as a prostatectomy; however, watchful waiting coupled with a pill could be more effective and contain fewer deleterious effects, said a study published Monday in The Lancet.
“The actual cancer poses very little threat to their life,” said Dr. Neil E. Fleshner of the University of Toronto and lead author of the study.
Men have a high chance of developing prostate cancer within their lifetime (16 – 18 percent), but only 3 percent of these patients are at risk of death, the study reported.
Robert Finke, 56, was diagnosed with non-aggressive prostate cancer six years ago and stayed on “active surveillance” – regular, perhaps quarterly, checkups by a specialist – until two months ago, when he underwent a robotic prostatectomy.
In 2006, Finke had a hard time finding a doctor who advocated a wait-and-see attitude, he said. He didn’t want to go through with an operation and have to live with possible urinary and sexual side effects, he added.
Some doctors recommend active surveillance if a patient has a small, slow-growing type of cancer because of the negative results — hair loss, nausea and vomiting — associated with more aggressive treatment options such as radiation therapy. Doctors perform periodic biopsies and only begin treatment when the cancer is becoming an escalating threat, Fleshner said.
The new study looked at 302 participants over three years. The men, aged 48 – 82, had a low-volume score for prostate cancer. A randomized sample received a daily 0.5-milligram dutasteride pill, a drug preventing testosterone from being converted to dihydrotestosterone, the male sex hormone that causes prostate cancer development.
Though 38 percent of the men receiving dutasteride experienced cancer progression, this number is 10 percent lower than the men who were given placebos.
The Food and Drug Administration has approved the medication to be used on men with benign prostatic hyperplasia or enlarged prostate.
“It appears that some of these men almost have vanishing cancers — when they’re so small we can’t detect them with the needles anymore,” Fleshner said.
Finke said if the study’s treatment regimen had been available to him when he was looking for alternatives to surgery, he would have taken the pill. “You’re always looking for the magic bullet,” he said.
At the end of three years, doctors were unable to detect cancer in 36 percent of men treated with dutasteride. Twenty-three percent of men given the placebo had no detectable cancer upon biopsy.
If this study is ever put into practice, it could help reduce overdiagnosis, where “cancers that probably don’t need to be found and therefore not need to be treated” are uncovered and harvested, Fleshner said.
The FDA warned doctors in June 2011 against using dutasteride for anything aside from benign prostatic hyperplasia because the drug could either have no effect or a harmful one on high-grade or highly developed prostate cancer.
Rather than aggravate the disease, dutasteride would actually aid in the detection of high-grade prostate cancer because it shrinks the prostate, Fleshner said.
Dr. J. Stephen Jones, chairman of the Cleveland Clinic Department of Regional Urology, agreed. It’s like a “duck in a big pond versus a duck in a small pond,” Jones said. “You’re more likely to shoot the duck in the small pond because there is less room to hide,” he said.
Patients taking dutasteride had adverse side effects such as impotence, ejaculation disorders and breast enlargement. Of those taking dutasteride, 24 percent experienced these effects; 15 percent of those taking the placebo felt them.
Fleshner and Jones said the side effects are “uncommon” and “reversible.” If someone is having a negative reaction, he could simply stop taking the medication, they said.
Dr. Scott Eggener at the University of Chicago Medicine said dutasteride is “an incredibly safe medication.” The study has “provocative data, and very interesting and relevant; however, it’s far from definitive because of the need for longer follow-up and larger studies,” he said.