Study Questions Some PSA Prostate Tests
Wednesday, December 3rd 2003, 12:00 am
By: News On 6
WASHINGTON (AP) _ Almost a third of men over 75 undergo laboratory blood tests each year to check their prostate health, but a new study questions the value of using the PSA test to screen men that old for prostate cancer.
``There is no evidence that screening men of this age would be beneficial to them, so this may not be the best use of health care resources,'' said Dr. Siu-Long Yao, a genital-urinary oncologist at the Cancer Institute of New Jersey in New Brunswick, N.J. He is senior author of the study appearing this week in the Journal of the National Cancer Institute.
``If you take all elderly men who die and do an autopsy, 30 to 70 percent will have prostate cancer, but they died of something else,'' said Yao. ``Diagnosing the prostate cancer may lead to unnecessary complications in elderly patients who are more likely to die of something else, such as cardiovascular disease.''
Researchers at the Cancer Institute analyzed a national survey of health reports and found millions of dollars are spent on annual tests for prostate specific antigen, PSAs. The test searches for abnormal prostate enlargement or growth.
The PSA test does not detect cancer directly. Instead, it determines, in effect, whether a patient has too much prostate tissue. That excess tissue can be caused by inflammation, by enlargement common to older men, or by cancer. A positive PSA test has to be followed up with a biopsy or other procedures before cancer can be confirmed.
The study was ``too simplistic,'' said Dr. Richard G. Middleton, a contributor to the prostate cancer guidelines for the American Urological Association.
``A routine PSA in a man over 75 would ordinarily not be necessary,'' but the blood test would be useful for a man with a history of prostate problems, said Middleton, chairman of urology at the University of Utah Medical School.
``There are many situations where the PSAs are helpful in monitoring and following an elderly man,'' he said. ``I object to the idea that it was somehow bad form to order a PSA on an elderly patient.''
Middleton said PSAs are needed to monitor for the recurrence of tumors in elderly men who have had surgery or radiation for prostate cancer earlier in life. PSAs also are appropriate, he said, for elderly men who have a suspicious-looking prostate on examination, who have a known tumor, or who have a previous history of an elevated PSA count.
In a survey of 7,889 men, researchers found that 32.5 percent of men over 75 received PSA blood tests _ an estimated 1.5 million men a year.
Medicare typically pays $25.70 for the lab work, federal officials said, suggesting that more than $38 million a year is spent on those tests for older men. Federal officials said more than $90 million was paid out last year for PSA tests for Medicare recipients of all ages.
``Most patients with an elevated PSA do not have prostate cancer,'' said Yao. Even if prostate cancer is first detected in a 75-year-old, the chances are very high that the patient will die of some other disorder before the slow-growing cancer could cause death, he said.
Yao said the study, based on data extracted from the National Health Interview Survey, showed that men over 75 are more likely to get a PSA test than a fecal occult test, a screening test that detects symptoms of colon cancer. Studies have shown that patients who get regular fecal occult tests tend to live longer than those who don't, he said, but there is no such evidence for a PSA test.
``What we found surprising is that something (PSA) with little proof of benefit was being used more commonly than tests (fecal occult) that have 20 years of proof behind them,'' said Yao.
Among the elderly men who participated in the survey, 88 percent said they got the PSA test at the advice of their doctor, but only 66 percent of those who got the test recall a discussion with the doctor about the risks and benefits of the test. For a test of questionable value, Yao said virtually all the doctors should have frank discussions with patients.