In a decision that has already sparked a backlash, a U.S. panel of experts today trashed a popular blood test for prostate cancer risk, saying its use is doing more harm than good.
Healthy men have no need to be screened by measuring levels of prostate-specific antigen (PSA) in circulation, concludes the U.S. Preventive Services Task Force, an independent group that advises the U.S. government. Men can skip the test, according to this panel, because it’s unreliable: Based on trial data it has prevented few deaths—at best potentially 1 in 1000 men screened. Yet the task force finds that for every 1000 men screened, the subsequent medical treatment leaves one with a blood clot, two with treatment-related heart attacks, and up to 40 with impotence or urinary incontinence. Overall, the task force didn’t think the benefits from PSA screening make it worth supporting.
The final recommendations are a big change from the task force’s previous stance in 2008. Back then, the panel held an equivocal view, saying that while men over age 75 should definitely avoid PSA screening, the benefits for younger men were “uncertain.” After studying recent clinical trials, however, the task force scrapped its hedged language and endorsed a clear negative. It now says that it “recommends against PSA-based screening for prostate cancer” regardless of age. The task force notes that this advice does not apply to men who have been diagnosed with or are being treated for cancer; the task force explains that it did not examine PSA surveillance for these patients.
Specialists in urology were prepared for this news and lashed out with an angry response. “The American Urological Association (AUA) is outraged at [the task force’s] failure to amend recommendations” issued last year in draft form, the association said in a statement issued today by President Sushil S. Lacy, a professor of urology at the University of Nebraska Medical Center in Omaha. He called today’s announcement a “disservice to American men”:
It is inappropriate and irresponsible to issue a blanket statement against PSA testing, particularly for at-risk populations, such as African American men. Men who are in good health and have more than a 10-15 year life expectancy should have the choice to be tested and not discouraged from doing so. There is strong evidence that PSA testing saves lives. … Rather than instruct primary care physicians to discourage men from having a PSA test, the Task Force should instead focus on how to counsel patients about their prostate cancer risk.
The chair of the task force, pediatrician Virginia Moyer at Baylor College of Medicine in Houston, Texas, acknowledged in a prepared statement that “there is a critical need for a better [prostate cancer] test—one that leads to early detection of cancers that threaten men’s health, but minimizes unnecessary, risky tests and treatments that do not lead to longer or more healthful lives.” In a commentary published along with the recommendations in the Annals of Internal Medicine, she argues for more research on ways to distinguish slow-progressing cancers from rapidly lethal ones and potentially to find better ways of modifying PSA test uses to reduce the high number of false positive results.
The controversy over PSA testing reflects some of the same concerns about government oversight of medical practice that arose in 2009 when the same task force (but with different members) downgraded the value of mammography as a way of preventing death from breast cancer. Like those guidelines, the prostate cancer recommendations may be debated in Congress. Already the Urological Research Foundation, whose medical director, William Catalona of Northwestern University’s medical school, opposes the task force recommendations, is telling readers of its Web site: “It's very important you let your congressional representatives know how you feel about these recommendations.”