US expert panel recommends against prostate cancer screening

The prostate specific antigen (PSA) test should not be used to screen
men for prostate cancer because it is unlikely to save lives and can
cause harm, says an independent panel of experts.

The US Preventive Services Task Force, an independent body of 16
experts that evaluates evidence to grade devices and rank preventive
services, announced its recommendation against prostate cancer
screening of all US men on 7 October. In a statement it said that
there was “moderate certainty that PSA-based screening for prostate
cancer has no net benefit.”

The task force made its recommendation in 2009 and again in 2010 after
in-depth scientific reviews conducted by the Agency for Healthcare
Research and Quality, but these were never published.

The agency’s 2010 review was published on 7 October after an article
in the New York Times magazine publicised the fact that this
recommendation was made, but not published, nearly two years earlier
(www.nytimes.com/2011/10/09/magazine/can-cancer-ever-be-ignored.html?_r=2&ref=magazine).

The review concludes: “The widespread US practice of annual PSA-based
screening for prostate cancer in men age 50 years and older is not
supported by results from randomized controlled trials. PSA-based
screening may modestly reduce prostate cancer mortality; this absolute
benefit is small relative to other causes of death in this age group
and is associated with substantial harms.”

It adds, “The vast majority of men treated for PSA-detected prostate
cancer will not have death from prostate cancer prevented.”

The review found “convincing” evidence that treatment of prostate
cancer detected through PSA screening causes “at least moderate harms,
such as erectile dysfunction, urinary incontinence, bowel dysfunction
and death.”

Philipp Dahm, professor of urology at the University of Florida
College of Medicine, said that the new recommendation is going to hit
the urology specialty “like a bomb.”

In 2008 the task force had given prostate cancer screening for men
aged 50 to 74 a grade “I”—indicating that there was not enough
evidence to recommend for or against screening. After an assessment of
the data the task force voted in November 2009 to change this to a
grade “D” recommendation because it “has no net benefit or that the
harms outweigh the benefits.”

The delay in announcing the 2009 grade D recommendation led to the
resignation of Kenneth Lin, one the scientific advisers to the task
force, who protested, saying that “politics trumped science” (BMJ
2010;341:c6346, doi:10.1136/bmj.c6346). Dr Lin was the lead scientific
reviewer at the Agency for Healthcare Research and Quality and
coauthor of its 2010 review, which is published on the task force’s
website (www.uspreventiveservicestaskforce.org).

The latest recommendation relied heavily on a meta-analysis published
in the BMJ in 2010 of which Dr Dahm was the lead investigator (BMJ
2010;341:c4543, doi:10.1136/bmj.c4543).

Dr Dahm told the BMJ that the confidence interval for the effect of
screening on mortality from all causes was “very narrow” and included
the possibility that screening provides a very small overall mortality
benefit—or a very small overall increase in mortality.

Dr Lin said that the meta-analysis is important because it was the
first study powered to assess all cause mortality. It reviewed five
studies, including the two largest trials to date, and evaluated
nearly 400 000 men who were randomised to one of two arms: a screening
arm using the PSA test or a control arm. It showed no significant
difference in all-cause mortality between men screened with the PSA
test and controls.

Publicity surrounding the recommendation has triggered an outcry by
some men, who say that their lives have been saved by routine
screening (www.nytimes.com/2011/10/09/magazine/can-cancer-ever-be-ignored.html).

Otis Brawley, chief medical and scientific officer for the American
Cancer Society, told the BMJ that it is impossible to say with
certainty that an individual man’s life was saved because many would
have lived anyway, as most prostate cancers never cause symptoms or
death. And some men are, he said, harmed by the invasive tests and
treatments that follow routine screening.

Currently, 33 million of the 44 million men aged over 50 in the US
have had at least one PSA test, and each year more than a million men
in the US undergo prostate biopsies. A study published last month
found that men who had a biopsy were twice as likely to develop
infection as age matched controls and that those who became infected
were 12 times as likely to die (Journal of Urology
doi:10.1016/j.juro.2011.06.057). In addition, most US men who learn
that they have prostate cancer opt for prostatectomy, and around one
in 200 of those men will die during the 30 day postoperative period.
Notes

Cite this as: BMJ 2011;343:d6479
Footnotes

The US Preventive Services Task Force’s draft recommendation is at
www.uspreventiveservicestaskforce.org/uspstf12/prostate/draftrecprostate.htm.