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PSA Discoverer Says PSA Screening is ”Public Health Disaster”

March 11, 2010 — Screening men for prostate-specific antigen (PSA), the most commonly used tool for detecting prostate cancer, has become a "hugely expensive public health disaster," says the researcher who discovered PSA in 1970.

Richard Ablin, PhD, research professor of immunobiology and pathology at the University of Arizona College of Medicine in Tucson, expressed his forthright views in a opinion piece entitled The Great Prostate Mistake, which was published in the New York Times on March 9.

The annual bill for PSA screening in the United States is at least $3 billion, he points out. But the test is "hardly more effective than a coin toss," he writes.

"It’s amazing to see the physician who discovered PSA take such a strong stance against it," said Elizabeth Whelan, ScD, MPH, from the American Council on Science and Health (ACSH). "The ACSH admires his courage and honesty in doing so," the organization noted in its daily dispatch. 

 Should Not Be Used For Screening

PSA screening is recognized as being an imperfect tool, and there is continuing ongoing debate about how best to use it.

In his opinion piece, Dr. Ablin writes: "As I’ve been trying to make clear for years now, PSA testing can’t detect prostate cancer." He points out that infections, over-the-counter drugs like ibuprofen, and benign swelling of the prostate can all elevate PSA levels. More important, the test cannot differentiate between prostate cancer that is rapidly growing and potentially fatal from one that is growing slowly and will not kill, he adds.

[PSA screening] should absolutely not be deployed to screen the entire population of men over the age of 50.
PSA testing does have a role, he says. One example is the use of the test to follow patients who have had treatment for prostate cancer, where a rapidly rising score indicates a return of the disease.

However, Dr. Ablin states categorically that PSA testing "should absolutely not be deployed to screen the entire population of men over the age of 50, the outcome pushed by those who stand to profit."

"Drug companies continue peddling the tests and advocacy groups push ’prostate cancer awareness’ by encouraging men to get screened," he asserts.

The medical community must confront reality.
"I never dreamt that my discovery 4 decades ago would lead to such a profit-driven public health disaster," Dr. Ablin says.

"The medical community must confront reality and stop the inappropriate use of PSA screening," he states. "Doing so would save billions of dollars and rescue millions of men from unnecessary, debilitating treatment."

Changing Attitudes

There are already some signs of changing attitudes. Two huge studies published last year showed that PSA screening had either no or little effect on the death rate from prostate cancer (N Engl J Med. 2009;360:1310-1319 and 1320-1328). These and other data have led to the realization that many men diagnosed with PSA screening are being overtreated.

The medical community is "slowly turning against PSA testing," Dr. Ablin writes. As evidence, he cites the new update to American Cancer Society guidelines published last month, which "urged more caution in using the test." In addition, the American College of Preventive Medicine has concluded that there is "insufficient evidence to recommend routine screening," he notes.

However, the American Urological Association (AUA) still recommends screening — "shamefully," according to Dr. Ablin. The National Cancer Institute is "vague on the issue, stating that the evidence is unclear." The Preventive Services Task Force recently recommended against PSA screening for men who are 75 year or older, but this group has still not made a recommendation either way for younger men, he notes.

AUA Remains in Favor

The AUA remains in favor of PSA screening, is contrast to some other medical bodies, as previously reported by Medscape Oncology. "The AUA believes that, when offered and interpreted appropriately, the PSA test may provide essential information for the diagnosis, pretreatment staging or risk assessment, and posttreatment monitoring of prostate cancer," according to a recent statement.

In a recent interview with Medscape Oncology, AUA spokesperson J. Brantley Thrasher, MD, from the University of Kansas in Lawrence, emphasized that PSA test results should not be considered on their own, but need to be interpreted along with other information.

I don’t want people to walk away from PSA and say it’s useless.
"PSA does not work well by itself in predicting prostate cancer," Dr. Thrasher said.

The interpretation of PSA tests by a urologist should always be done in conjunction with other factors that contribute to prostate cancer risk, such as overall health, family history, age, comorbidities, the rate of change in PSA value over time (PSA velocity), and physical examination, Dr. Thrasher explained, referring to the AUA’s Prostate-Specific Antigen Best Practice Statement.

"I don’t want people to walk away from PSA and say it’s useless," he remarked. "We believe we are still saving lives with the test."

http://www.medscape.com/viewarticle/718351
Đăng bởi: ycantho - Ngày đăng: 10/01/2011