By Gary Schwitzer
I asked one of our medical editor/story reviewers, Richard M.
Hoffman, MD, MPH, to write about the news stories predicting what the U.S.
Preventive Services Task Force will recommend on prostate cancer
screening.
Hoffman
is a general internist, a professor of medicine at the University of
New Mexico School of Medicine, and a staff physician at the Albuquerque
VA Medical Center. He also serves as Interim Director for Cancer
Prevention at the University of New Mexico Cancer Center. His areas of
research interest are prostate and colorectal cancer screening and
prostate cancer treatment outcomes, with expertise in clinical
epidemiology, health services research, and meta-analysis. He is a
medical editor for prostate cancer topics for the Foundation for
Informed Medical Decision Making and works with the foundation to
develop shared decision-making tools for prostate cancer screening and
treatment of localized prostate cancer. The foundation is also the sole
financial supporter of my HealthNewsReview website.
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Once again, the United States Preventive Services Task Force (USPSTF) seems
headed for a storm of controversy. The New York Times reported last week
that the task force will issue draft recommendations next week advising
against prostate cancer screening. The task force concluded that
screening should be discouraged because it has no net benefit or the
harms outweigh the benefits.
Not even two years ago, the task force’s recommendation against
routinely performing mammography in average-risk women before age 50
outraged professional organizations, advocacy groups, celebrities,
politicians, and many other vocal critics. Unfortunately, the somewhat
awkward message was distorted to imply that these women should never
undergo mammography. In fact, the task force was highlighting that
mammography for these women involved important trade-offs between
potential benefits and harms — and that women needed to make informed,
personalized decisions. This is an appropriate message.
However, the new recommendation on prostate cancer seems troubling.
In 2008, the task force gave prostate cancer screening an "I" rating
because the available evidence was considered insufficient to recommend
for or against screening — largely because there were no valid data from
randomized controlled trials of screening. The task force suggested
that men be informed about the risks and benefits of screening, though
it strongly advised against screening men age 75 and older.
In 2009, long-awaited results from the major randomized controlled
trials were published. The European Randomized Study of Screening for
Prostate Cancer (ERSPC) found that screening reduced prostate cancer
mortality by 20%. In contrast, the American Prostate, Lung, Colorectal,
and Ovarian Cancer Screening Trial (PLCO) found no benefit with
screening. However, evaluating prostate-specific antigen (PSA) in America was challenging because
screening was so pervasive that investigators had difficulty enrolling
men who had never been screened — or preventing screening in the control
group. The validity of the negative PLCO results is uncertain. The
ERSPC study was more credible, but showed only a small absolute survival
benefit. This benefit must be balanced against the harms of
overdiagnosis — finding cancers that would never cause clinical problems
during a man’s lifetime — and the resulting overtreatment, which can lead
to urinary, bowel, and sexual dysfunction.
Unfortunately, we cannot confidently identify the "overdiagnosed"
cancers found with screening, so most men will undergo surgery or
radiation therapy. A new strategy of active surveillance might mitigate
the harms of overdiagnosis. With this option, men are closely
monitored with PSA tests, digital rectal examinations, and biopsies — and
will be offered surgery or radiation only if the cancer shows signs of
being aggressive.
Ideally, men should be making an informed decision that best reflects
their values for the potential downstream consequences of screening.
This is indeed the conclusion (based on similar clinical data) that the
Task Force reached regarding mammography for women before age 50. The
Task Force classified this as a grade "C" recommendation — which is what I
expected for prostate cancer screening.
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Publisher’s note: Anyone who is not familiar with the USPSTF’s grading system should read about it. The difference between a C and D recommendation is significant.
Another very thoughtful commentary has been posted by Dr. Len Lichtenfeld of the American Cancer Society. Excerpt:
"We have invested over 20 years of belief that PSA
testing works. Catch it early, treat it early, and get it out. Save a
life. That’s the mantra many of us — including me, as a practicing
physician — believed. And here we are all of these years later, and we
don’t know for sure. That is not an acceptable situation. Plain and
simple, we have not done our homework to prove our point. And the
chickens are coming home to roost.
Unfortunately, those "chickens" are men like me who dutifully get our
blood tested every year. We have been poked and probed, we have been
operated on by doctors and robots, we have been radiated with fancy
machines, we have spent literally billions of dollars. And what do we
have? A mess of false hope?"
A decision aid on prostate cancer screening, produced by the Foundation for Informed Medical Decision Making, is now available online for a limited time.
One interesting aspect is that it features two doctors — one who
chooses to be screened using the PSA blood test, and one who declines.
Finally, when CNN broke its version of the USPSTF prostate story, it reported that:
"The U.S. Preventive Services Task Force, the group that
told women in their 40s that they don’t need mammograms, will soon
recommend that men not get screened for prostate cancer, according to a
source privy to the task force deliberations."
Wrong. That’s not what the USPSTF said about mammography.
A. The US Preventive Services Task Force makes recommendations to primary care physicians.
B. Here’s what they actually wrote about mammography:
"The decision to start regular, biennial screening
mammography before the age of 50 years should be an individual one and
take into account patient context, including the patient’s values
regarding specific benefits and harms."
No matter how you spin it, that’s simply NOT telling women that they don’t need mammograms.
Journalists’ mishandling of the USPSTF mammography recommendations to
primary care medicine resulted in rampant consumer confusion.
Will we relive that with the new prostate cancer screening recommendations?