Reuters - PSA test for prostate cancer not recommended: panel
October 26, 2011 Fri, Oct 7 2011
http://www.reuters.com/article/2011/10/07/us-cancer-prostate-idUSTRE79605220111007
REUTERS
CHICAGO (Reuters) - Doctors criticized proposals by a government-backed panel recommending against prostate cancer screening in healthy men -- saying they went too far and may put some men at risk of the deadly cancer.
The U.S. Preventive Services Task Force, which advises the government on health prevention measures, on Friday downgraded its recommendation on prostate cancer screening to a "D," which means it recommends against the service because "there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits."
It had previously said there was not enough evidence to make a call on the use of prostate-specific antigen, or PSA, tests that measure levels in the blood of a protein.
The task force made its recommendation based on a review of scientific evidence that suggested the benefits of fewer cancer deaths was overshadowed by potential serious side effects from treating a cancer that might never have caused any harm.
The same panel caused a media storm in 2009 after it recommended doctors scale back on routine mammograms for women in their 40s and 50s.
"Prostate cancer remains the second-leading cause of cancer death in the United States," Dr. Scott Eggener, a surgeon who specializes in prostate cancer at the University of Chicago.
He said while not perfect, PSA screening has definitely saved lives, noting that widespread PSA screening in the United States has resulted in a 30 percent decrease in death rates when adjusted for men's ages.
Several European clinical trials have also shown PSA screening saves lives, Eggener said.
"Put simply, when PSA screening is used, fewer men develop metastatic prostate cancer or die from it," he said.
SEVERAL CAUSES OF HIGH PSA
High or increasing levels of PSA can indicate an increased risk for prostate cancer, but elevated PSA levels can be caused by other things too, such as infections, an enlarged prostate or even recent ejaculation.
Studies have shown that widespread use of PSA tests has resulted in high rates of false positives and overtreatment for cancers that might never have caused harm.
And the treatments -- usually surgery and radiation -- are not benign. They often result in impotence and incontinence.
Simply being diagnosed with prostate cancer can cause anxiety and harm. A study by researchers at Harvard and Brigham & Women's Hospital in Boston last year found that being diagnosed with prostate cancer roughly doubles the risk of suicide or death from a heart attack.
Results of studies looking at the benefits of widespread prostate cancer screening have been mixed, according to the conclusions of a review of studies set to be published next week but released early by the Annals of Internal Medicine.
That review, which is used by the task force to make its recommendations, noted that of the five screening trials it studied, the two largest and highest-quality studies reported conflicting results. One found screening was associated with reduced prostate cancer deaths compared with no screening in men age 55 to 69 after nine years.
The other found no statistically significant benefit after 10 years. And of the men who had three or four rounds of screening, the false positive rate was 12 to 13 percent.
"Prostate-specific antigen-based screening results in small or no reduction in prostate cancer-specific mortality and is associated with harms related to subsequent evaluation and treatments, some of which may be unnecessary," the report concluded.
TOO DRASTIC
Critics said the studies were too short and argued that there is evidence that PSA screening saves lives.
"I think they are a little premature," said Dr. Andrew Lee, a radiation oncologist at University of Texas MD Anderson Cancer Center.
Lee said moving from saying there is not enough information to saying a test is recommended is too drastic given that the evidence is so inconclusive.
"I know some of the studies did look bad," Lee said. "In my personal review of the literature, there are arguments both ways. If that is the case, as a physician I would err on the side of being more conservative.
"I don't think the data is at all conclusive to make such a strong recommendation as a 'D' rating," he said.
Dr. Herbert Lepor, a urology professor at New York University School of Medicine, said the claim that screening studies fail to show a benefit is inaccurate, pointing to a Scandinavian study with 14 years years of follow up that showed screening cut prostate cancer deaths by 50 percent.
"The U.S. Preventive Services Task Force is a group of primary care physicians like pediatricians and OB/GYNs who never treat prostate cancer. They have simply misinterpreted the studies and have not seen men die of this fatal disease," Lepor said.
The proposed guidelines are meant to discourage PSA testing in healthy men; they do not apply to men suspected of having prostate cancer.
They had been scheduled to be released in the Annals of Internal Medicine on Monday, but leaks of the recommendations to news outlets forced the group to post the guidelines early. It was first reported by CNN on Thursday.
The recommendations will be available for a 30-day comment period before final treatment guidelines are released.
According to the American Cancer Society, about 1 man in 6 will be diagnosed with prostate cancer in his lifetime. More than 2 million U.S. men who have been diagnosed with prostate cancer at some point are still alive today.