Doctors urge baseline test for prostate cancer
April 27, 2009
An influential doctors group is backing off its call for annual tests after age 50 to screen for prostate cancer.
“Many men do not need yearly screening,” but each man’s risk should be individually assessed, said Dr. Peter Carroll, who led the panel that wrote the American Urological Association’s new guidelines. They are being issued Monday at the group’s annual meeting in Chicago.
The new stance brings the group more in line with advice from other experts, who say annual screening is leading to unnecessary biopsies and treatment with little proof that it saves lives. Screening involves a physical exam and a blood test for a substance called PSA.
The urology group’s new advice says men should be offered a baseline PSA test at age 40, and follow-ups at intervals based on each man’s situation. A high PSA at age 40 greatly predicts a risk of prostate cancer, said Carroll, a urologist at the University of California at San Francisco.
Doing a baseline test “makes a lot of sense to me,” said Dr. Eric Klein, prostate cancer chief at the Cleveland Clinic.
Others disagreed. There is no proof that a baseline test will save lives, said Dr. Barnett Kramer, a National Institutes of Health scientist.
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“The same issue of harm comes up ” overdiagnosis. A baseline PSA, just like regular PSA screening, can lead to the diagnosis of cancers that would not have harmed a man had they not been detected,” Kramer said.
Prostate cancer is the most common non-skin cancer in American men. An estimated 186,000 new cases and 28,660 deaths from it occurred last year.
Cases rose in the late 1980s with the start of testing for prostate-specific antigen, or PSA, a substance the prostate produces when it is inflamed. Despite its name, PSA isn’t very specific. It can rise for many reasons besides cancer, such as normal prostate enlargement as men age, use of certain medicines ” even things like a hard bike ride or recent sex.
Two big studies last month concluded that annual PSA tests do little to prevent deaths from prostate cancer. But many doctors believe the test may still have value ” if researchers can figure out better ways to use it.
New studies at the urology meeting suggest ways. One found that a man’s PSA at age 60 can strongly predict whether he ultimately will die of the disease.
Dr. Hans Lilja of Memorial Sloan-Kettering Cancer Center in New York tested stored blood samples from nearly 1,200 Swedish men from the early 1980s and checked cancer registries to see how many later developed or died of prostate cancer.
If PSA was 1 or less at age 60, the risk of dying of prostate cancer by age 85 was very low ” less than 1 percent ” even if men had the disease for many years. About 90 percent of cancer deaths occurred in men whose PSAs at age 60 were in the top one-fourth of the group.
In a different study, Dr. E. David Crawford of the University of Colorado Health Sciences Center studied 29,000 men from one of the large screening studies reported last month. Only about 1 percent of those whose initial PSA test was under 1 saw their scores rise above 4 in the next five years. Those with higher baseline scores had a much greater chance of that happening.
“The bottom line is if you’ve got a PSA of less than one in your initial screen, you can wait to get another PSA for five years and not really be at increased risk of missing a cancer,” he said. “If your PSA is between 1 and 2, it’s also a small risk.”
Crawford is the unpaid chairman of the Prostate Conditions Education Council, an industry-supported group that promotes screening.
Dr. Robert Uzzo, a prostate surgeon at Fox Chase Cancer Center in Philadelphia, said many doctors are already advising longer testing intervals.
“Everybody has to get screened at least at some baseline” to sort out future testing needs, he said. “If the baseline is quite low then I don’t insist on yearly screening.”
Dr. Otis Brawley, the American Cancer Society’s chief medical officer, believes there is still some value to PSA testing, but added: “I am very concerned that the urology community and the American public may think there’s more value in PSA than there actually is.”
Urology group: http://www.AUAnet.org/
Government advice: http://www.ahrq.gov/clinic/cps3dix.htm.cancer
Risk calculator: http://tinyurl.com/cys84m