The New York Times and Cancer Letter reported Thursday that the U.S. Preventive Services Task Force (USPSTF) will recommend early next week that men aged 50 and over not undergo routine prostate-specific antigen (PSA) screening for prostate cancer.
Both publications are reporting that the task force intends to downgrade its recommendation for the PSA test from its current “I” (incomplete evidence) grade to “D.” According to the USPSTF website, a “D” rating means “there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefit.” The rating is also meant to “discourage the use of this service.”
“Unfortunately, the evidence now shows that this test does not save men’s lives,” Dr. Virginia Moyer, a professor of pediatrics at Baylor College of Medicine and chair of the task force, told New York Times reporter Gardiner Harris. “This test cannot tell the difference between cancers that will and will not affect a man during his natural lifetime. We need to find one that does.”
The USPSTF is an independent panel of experts that evaluates the latest scientific evidence regarding preventive tests and screening and then makes recommendations based on that evidence.
The news about the USPSTF draft recommendation for PSA testing (it won’t be finalized for several weeks) has already set off a controversy. (Just read the comments to the Times’ article.) The criticism is reminiscent of that which erupted in 2009 when the task force said women in their 40s need not undergo routine mammograms for breast cancer but should instead make a personal decision about the screening test after carefully weighing its risks and benefits.
The political pushback to the mammogram recommendation was huge. As Paul Goldberg writes in the Cancer Letter, “Insiders are wondering whether the [Obama] administration will stand by another negative recommendation from the task force — or whether it will back down, as it did during the mammography debate.”
A decision twice delayed
According to a second article in the New York Times, one that’s running in its Sunday magazine, the task force was ready to publish its “D” grade for prostate screening in 2009, but held off because of the furor that arose over its mammogram recommendations. It postponed the decision again a year later — right before the 2010 Congressional midterm elections — out of fear it would lose its funding.
But the evidence suggesting the PSA test does more harm than good has been building for years. Writes Harris:
As the P.S.A. test has grown in popularity, the devastating consequences of the biopsies and treatments that often flow from the test have become increasingly apparent. From 1986 through 2005, one million men received surgery, radiation therapy or both who would not have been treated without a P.S.A. test, according to the task force. Among them, at least 5,000 died soon after surgery and 10,000 to 70,000 suffered serious complications. Half had persistent blood in their semen, and 200,000 to 300,000 suffered impotence, incontinence or both. As a result of these complications, the man who developed the test, Dr. Richard J. Ablin, has called its widespread use a “public health disaster.”
Prostate cancer is diagnosed in about 192,000 American men each year. It’s also the second-leading cause of cancer deaths among American men (behind lung cancer). Yet, as Shannon Brownlee, acting director of the New America Foundation Health Policy Program, and freelance medical writer Jeanne Lenzer point out in their Sunday Times article, most of the men currently being diagnosed with the disease will not die from it — even if they go untreated:
A small number of tumors are very aggressive, but the majority of prostate tumors are not likely to cause death. They grow very slowly, and only a fraction break out of the prostate, seed new tumors in other parts of the body and kill the patient. The current thinking is that about 30 percent of men in their 40s have prostate cancer, 40 percent of men in their 50s and so on, right up to 70 percent of men in their 80s. Yet only 3 percent of all men die from the disease. In other words, far more men die with prostate cancer than from it, and only a tiny fraction of prostate cancers ever cause symptoms, much less death.
Critics of the new USPSTF prostate cancer screening recommendations worry that those men whose lives might be saved from the test will now have their malignant cancers diagnosed too late. But supporters of the recommendations look at it differently. They point to the harm that the testing does. Dr. David Newman, an emergency room physician and a director of clinical research at Mount Sinai School of Medicine in Manhattan, gave Brownlee and Lenzer a powerful metaphor to explain the dilemma that faces men about whether or not to get tested:
“Imagine you are one of 100 men in a room,” he says. “Seventeen of you will be diagnosed with prostate cancer, and three are destined to die from it. But nobody knows which ones.” Now imagine there is a man wearing a white coat on the other side of the door. In his hand are 17 pills, one of which will save the life of one of the men with prostate cancer. “You’d probably want to invite him into the room to deliver the pill, wouldn’t you?” Newman says.
Statistics for the effects of P.S.A. testing are often represented this way — only in terms of possible benefit. But Newman says that to completely convey the P.S.A. screening story, you have to extend the metaphor. After handing out the pills, the man in the white coat randomly shoots one of the 17 men dead. Then he shoots 10 more in the groin, leaving them impotent or incontinent.
Newman pauses. “Now would you open that door?” He argues that the only way to measure any screening test or treatment accurately is to examine overall mortality. That means researchers must look not just at the number of deaths from the disease but also at the number of deaths caused by treatment.
The USPSTF draft recommendations will be published on its website Tuesday. Get ready for the pushback.