 In
the war against prostate cancer, that scourge of men's health, we're still poorly
armed. For diagnosis we often need to make an unpleasant choice between PSA tests
or digital rectal exams (DRE). The Canadian Cancer Society says 20,100 men will
be diagnosed with prostate cancer this year and roughly 4,200 will die from it,
so we need to get the best possible results from our oncological arsenal. And
some say that PSA screening isn't doing its part in the battle against prostate
cancer. If you're an advocate of PSA screening,
Dr Wayne Elford, professor emeritus in the University of Calgary's department
of family medicine urges you to pick up the October issue of The Journal of
Urology. In the article "The Prostate Specific Antigen Era in the United States
is over for Prostate Cancer: What happened in the last 20 years," the authors
found in the last five years, serum PSA has only been helpful in spotting prostate
cancer in men with benign prostatic hyperplasia. PSA
serves as a biological marker for disease, and blood test results are reported
as nanograms of PSA per millilitre (ng/ml). Many doctors previously thought that
values below 4ng/ml were normal. Recent research, however, has shown that it's
not so clear-cut and that even men with levels below this have developed prostate
cancer. THE
BOTTOM LINE
So do PSA levels give doctors enough information to detect
cancer? "Not at all," says Dr Elford. "I have never favoured widespread use of
PSA screening. There's no gold standard test for screening for prostate cancer
to compare PSA screening against and it has never appeared that PSA should be
the standard." Dr Elford believes there's likely more
than one type of prostate cancer just like there's more than one type of breast
cancer but science hasn't yet learned how to differentiate the different types.
And he cautions against radical treatment of early stage prostate cancer. "It's
like shooting at flies with a bazooka," he says. "A significant number of early
stage prostatic cancers progress so slowly that the patient is more likely to
die from some other cause." TOO
MUCH, TOO SOON
And according to Dr Elford, increased PSA levels can
lead to sometimes unnecessary invasive tests, such as a biopsy. Potential side
effects of a biopsy include hematospermia (blood in the ejaculate or sperm) and
hematuria (blood in the urine), just to name a couple. "Over the last decade,
increased PSA levels have been triggering increasingly aggressive diagnostic and
treatment modalities that are associated with significant morbidity in themselves
— while all the time not appearing to impact the all-cause mortality rates,"
says Dr Elford. Although he opposes widespread PSA
screening, Dr Elford does believe that it serves an important purpose. "I feel
that the major role of the test is monitoring the response to treatment of patients
with prostate cancer," he says. "But as for using PSA levels as a marker for prostate
cancer, it's tenuous at best." — By Marcello
Palmieri
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