Commentary-  PSA Test for the Asymptomatic Man?

In a recent article in the New York Post (25 July, 2001) New York's Mayor Rudolph Giuliani urged all men over 50 to have a PSA test. Mayor Giuliani's interest in prostate health is well founded. However, the discovery I made in 1970 of PSA which led to the development of the PSA test for the diagnosis of prostate cancer has unfortunately never been specific enough to be a definitive test for that disease, resulting for many men in unnecessary anxiety and biopsies. (The facts here are that with an elevated level of PSA in the blood being greater than 4 ng/ml, PSA misses up to 40% of patients with prostate cancer and provides false-positives in the "diagnostic questionable [gray] range" of 4-10 ng/ml in up to 80% of patients and in which only 25% will be found to have prostate cancer on biopsy.) Diminished early enthusiasm has been buoyed by the introduction of PSA-related concepts, the latest and most popular of which is the % free PSA, in an endeavor to improve the specificity of PSA testing and in discriminating would-be-biopsy-negative from biopsy-positive patients. The fact that the latter, i.e., PSA-related concepts, are technically flawed (See: Ablin, R.J. The Lancet Oncology, 1:13, 2000) and often lead to treatments which may be unnecessary and/or in themselves are associated with a high incidence of morbidity has nonetheless been obfuscated by media attention to high-profile figures, such as Mayor Giuliani, and major business interests. (The worldwide market for PSA testing in the year 2000 was approximately $300 million and is increasing.) In quoting Doctor Barnett Kramer, Director of the Office of Medical Applications and Research, National Institutes of Health and Editor-in-Chief of the Journal of the National Cancer Institute, "... in prostate cancer, estimates of overdiagnosis range from about 10% or 15% of screen-detected cases to more than 50%." (Oncology News Int'l., 10(5):3, 2001).
 
In essence, the medical community today, buoyed by media hype and aggressive marketing, downplays the downsides of the PSA test and screening for prostate cancer, i.e., ambiguous results, possibly unnecessary treatment and the use of treatments that are far from definitive; and, the fact, that in some cases failed treatment of early cancers has converted slow growing to more threatening tumours.
 
I can only hope that in the near future a more specific test is developed, particularly one that will permit distinction of threatening from nonthreatening early cancers, i.e., the killers from the "sleepers" that will lead to more sensible strategies and improved methods for the treatment of prostate cancer. In the interim, we should, at best, look upon the PSA test for the "asymptomatic man" as a "smoke" vs. a "fire" alarm, telling us there is something to follow-up on. Within this framework Mayor Giuliani's concern is worthy of consideration. For further information on PSA, and prostate cancer visit http://www.prostatefoundation.org

 

Richard J. Ablin, Ph.D.

President, Robert Benjamin Ablin Foundation for Cancer Research
115 Franklin Turnpike, Suite 200
Mahwah, NJ  07430
E-mail: ablinrj@prostatefoundation.org

 

 

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