Experts Back Away From Annual PSA Test
MONDAY April 27, 2009 -- New guidelines on prostate cancer screening suggest that annual PSA blood tests might not be necessary for many men, but the same guidelines call for a "baseline" PSA test at the age of 40, rather than 50.
A prostate-specific antigen (PSA) test to detect early signs of prostate cancer should be offered to "well-informed men aged 40 and older who have a life expectancy of 10 years," state clinical guidelines issued Monday by the American Urological Association at its annual meeting in Chicago.
Noting that the issue of PSA testing and how it should be used to guide treatment "is highly controversial," the association still stated that the test, "when offered and interpreted appropriately, may provide important information for the diagnosis, pre-treatment staging or risk assessment or post-treatment monitoring of prostate cancer."
But it's important that "the risks and benefits of PSA screening be discussed with men before the test is done," said Dr. Peter Carroll, chairman of the department of urology at the University of California, San Francisco, who headed the committee that drew up the new guidelines.
Those risks can include impotence and incontinence caused by unnecessary surgery.
The recommendation that a first PSA test be offered to men at 40 should help doctors spot high-risk patients more readily, however. "PSA at that age is strongly predictive of the future risk of prostate cancer," Carroll said. "Later detection in the 50s, when the cancer would be more advanced, could be avoided."
The guidelines also recognize that many prostate cancers grow so slowly that they are of no risk, he said. Further steps after detection of an elevated level of PSA, a protein produced by the prostate, should require consideration of "other risk factors, such as family history and ethnicity," Carroll said.
Another major change is that the guidelines set no specific PSA blood level as an indicator of danger, he said. The danger level for an individual man will depend on other risk factors.
And yearly PSA tests might not be needed for many men, the guidelines note. "Screening less frequently may be a less costly way to screen," Carroll said. No specific timetable for less frequent screening is set in the guidelines, but they might be recommended as more information becomes available, he said.
The new guidelines did take into account two recent studies, one in Europe which found that regular PSA screening reduced prostate cancer deaths, and one in the United States which found no effect of screening, Carroll said. The U.S. study was flawed in several ways, he noted. For example, it permitted men who were not assigned to the group for screening to go have PSA tests on their own.
"Both studies do not suggest that PSA screening should not be undertaken," Carroll said.
New information on PSA testing has been a major focus at this year's AUA meeting. One study by urologists at the University of Colorado focused on the timing of PSA tests. The study, which followed more than 76,000 men for at least five years, found that the PSA levels of nearly 99 percent of men with very low readings on an initial test would remain low for at least five years. That suggests that limiting tests to every five years for men at that low level, and to every two years for men with slightly higher readings, would lower the overall need for PSA tests by 70 percent, reducing testing costs by $1 billion a year, the researchers reported.
On the other hand, a Swedish study found that PSA readings at age 60 were strong indicators of increased prostate cancer death risk. But "60 -year-old men with PSA at or below 1 nanogram per milliliter [a low reading] can be told that although they harbor prostate cancer, it is very unlikely to become life-threatening," the researchers wrote.
A third report at the meeting took issue with the recommendation of the U.S. Preventive Task Force that men aged 75 and older should not have PSA tests at all.
Dr. Judd W. Moul said that when he read that recommendation, he did a poll of 340 older men at the Duke University Prostate Center, which he heads. "My immediate reaction was that it was age discrimination," he said.
The survey, done by Duke medical students, found that 78.2 percent of the men were upset by the recommendation, said Moul, an outspoken proponent of PSA testing.
Moul acknowledged that the report had been refused publication by a medical journal on the grounds that it was biased. But he said the advice to stop PSA testing after 75 "was supported neither by public opinion nor by our outcomes data."
A thorough description of PSA testing is given by the U.S. National Cancer Institute.
Posted: April 2009
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