Prostate Cancer Surgery Fails to Cut Death Rate in Study
Surgery for prostate cancer was no better in saving lives than observation over a 10-year period, according to one of the first rigorous studies to compare the two approaches in American men with early-stage disease.
The U.S.-funded study assigned 731 men across the country with early prostate cancer to have the gland surgically removed or be observed without any attempt at curative treatment. Ten years later, 47 percent of men in the surgery group had died, mostly from other diseases, versus 49.9 percent who were just watched, results published in the New England Journal of Medicine found. The difference wasn’t statistically meaningful.
The study is certain to fuel the debate over whether doctors are aggressively treating prostate cancer in men who aren’t likely to die from it, causing side effects such as incontinence and impotence.
“There is no question in my mind that what we have been doing in the United States for the last 20 years has hurt a lot of men needlessly,” said Otis Brawley, chief medical officer for the American Cancer Society. “We need to be telling men that there is tremendous evidence that a large number of men with prostate cancer could be watched and don’t need to be treated.”
The study, while too small to rule out a modest life-saving benefit from surgery, is relevant to the debate over excess prostate cancer screening and treatment because it included patients whose cancer was detected through PSA testing. In May, the U.S. Preventive Services Task Force recommended against using the prostate-specific antigen blood test to spot the disease, saying the screening leads to overtreatment and unnecessary side effects.
More than 241,000 American men are diagnosed with prostate cancer each year, and more than 28,000 die from it, making it the second-leading cause of cancer death in men, according to data from the American Cancer Society. The vast majority of cases are discovered in the local and regional stages, where the survival over five years is almost 100 percent.
Currently, only 10 percent of American men with prostate cancer who are eligible for observation choose observation, according to a National Institutes of Health report last year. The vast majority elect surgery or various forms of radiation in an attempt to cure their cancer. Both forms of treatment have side effects, including impotence.
“When men hear cancer they want something done,” said Durado Brooks, director of prostate and colorectal cancers for the cancer society. The idea that some prostate cancers aren’t life-threatening is “very difficult for people to accept because they are accustomed to thinking of cancer as this ravaging, always-lethal condition.”
While the study originally intended to include 2,000 patients, the size was reduced to 731 men because of the difficulty in getting men to enroll, researchers said. This limited the study’s ability to parse out small differences in death rates, said Brawley of the cancer society. Nonetheless, the result indicates that prostate surgery for localized cancer detected through PSA tests saves very few lives, he said.
After a median of 10 years, 171 of 364 men assigned surgery had died, while 183 of 367 assigned to observation died. In the surgery group, 5.8 percent of the men died from prostate cancer compared with 8.4 percent of the men in the observation group. Neither difference was statistically significant.
More than 1 in 5 patients in the surgery group had complications within 30 days of the operation. Urinary incontinence and erectile dysfunction were much more common in men who got the surgery, while men who got observation had a higher rate of developing bone metastases.
“The results are consistent with emerging science suggesting that for the vast majority of men observation can be a wise and preferred treatment choice” if they have localized prostate cancer, said Timothy Wilt, a researcher at the Center for Chronic Disease Outcomes Research at the Minneapolis Veterans Affairs Health Care System, and the study’s lead author.
The results supporting observation were most robust in men with whose PSA levels were 10 nanograms per milliliter or less when cancer was detected, Wilt said. This was about two-thirds of the patients in the study.
Doctors used to consider a PSA above 4 as high and a cutoff for further evaluation.
The death rate from prostate cancer among the patients with lower PSA levels was the same regardless of whether patients got surgery or observation, the study found. In patients with higher PSA levels, surgery significantly reduced all deaths and prostate cancer deaths, the study found.
The new results contrast with a Scandanavian study of surgery versus observation. After 12.8 years, the trial of 695 men from Sweden, Finland and Iceland, found that surgery prevented 1 prostate cancer death for every 15 patients who got surgery, according to the most recent research update published in 2011. The benefit from the surgery was confined to men younger than age 65.
While the reason for the divergent results are unclear, one difference between the studies is that the Scandanavian study was conducted before PSA testing became common, and thus included more people with larger tumors that were only detected on a digital rectal exam, Wilt said.
The study led by Wilt was sponsored by the U.S. Department of Veterans Affairs, the National Cancer Institute, and the Agency for Healthcare Research and Quality.
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