PSA test for prostate cancer should be dropped, task force says
The PSA test should be abandoned as a prostate cancer screening tool, a government advisory panel has concluded after determining that the side effects from needless biopsies and treatments hurt many more men than are potentially helped by early detection of cancers.
At best, one life will be saved for every 1,000 men screened over a 10-year period, according to the U.S. Preventive Services Task Force. But 100 to 120 men will have suspicious results when there is no cancer, triggering biopsies that can carry complications such as pain, fever, bleeding, infection and hospitalization.
And if cancer is detected, 90% of men will be treated with surgery or radiation even though most tumors are not life-threatening.
Of 1,000 screened men, as many as 40 will suffer impotence or urinary incontinence as a side effect of treatment, two will have heart attacks or strokes and one will develop a dangerous blood clot in the legs or lungs, the task force concluded after a review of the scientific literature. As many as five of 1,000 men who undergo surgery will die within a month.
“There is a small potential benefit and a significant known harm,” said Dr. Virginia A. Moyer, a professor of pediatrics at Baylor College of Medicine in Houston, chairwoman of the task force. The PSA test, she said, “should not be part of your checkup.”
Instead, men who want to protect their health should talk with their doctors about prostate-related problems, such as issues with urinary flow, said task force member Dr. Michael LeFevre of the University of Missouri in Columbia. The digital rectal exam is also an option, he added, although there is not much support for that exam either.
In presenting its final recommendations, the expert panel also acknowledged that “some men will continue to request screening and some physicians will continue to offer it.” Should they go ahead, doctors and patients must carefully discuss the pluses and minuses.
But mass screenings at fairs, workplaces, shopping malls and other community sites should end because they rarely involve discussion of risks and tend to emphasize that PSA screening saves lives, the task force added.
The report, released online Monday in the journal Annals of Internal Medicine, was welcomed by some doctors who have worried for years that American men are being over-screened for prostate cancer, leading to unnecessary and often dangerous medical procedures.
It dismayed others who believe that the test saves lives and that dumping it would result in more cases of advanced prostate cancer as well as deaths from the disease, which is expected to kill about 28,000 men in the U.S. in 2012.
The advice is “outrageous,” said Dr. William J. Catalona, a urologist at Northwestern University Medical School in Chicago who co-wrote a commentary in Annals that argued the task force had erred in its interpretation of the science.
“PSA testing is really a boon to men, and they’re throwing it out because they underestimate the benefits and overstate the harms,” he said.
The American Urological Assn. also released a statement disputing the task force recommendations.
But Dr. H. Gilbert Welch, a professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice in Hanover, N.H., said the advice was “a courageous call — I think it’s the right call.”
“I’ve thought about this for myself and I’ve concluded that it’s just an awful deal,” said Welch, author of “Overdiagnosed: Making People Sick in the Pursuit of Health.” “There’s probably some benefit, but it’s so small and the harms are so much more common. And they matter.”
PSA, or prostate-specific antigen, is an enzyme that helps liquefy semen. When prostate cancers develop, PSA levels in the blood can start to climb. Other medical conditions, such as prostate inflammation and benign prostatic hyperplasia, can also cause PSA levels to rise.
The test has been routinely used as a screen for prostate cancer starting in middle age since the 1990s. The precise level of PSA in the blood or patterns of PSA change deemed suspicious vary somewhat from practice to practice.
About 16% of men will receive a prostate cancer diagnosis in their lifetimes, and 2.8% will die of it, according to the National Cancer Institute. Seventy percent of prostate cancer deaths occur in men over age 75.
The task force recommendations say nothing about using the PSA test as a way to track a cancer once it has been diagnosed, Moyer said. Nor do they involve any consideration of costs.
How could early detection of prostate cancer be anything but beneficial? One problem is that most cancers found through PSA tests aren’t dangerous because they grow slowly or not at all, said Dr. Otis Brawley, chief medical officer of the American Cancer Society. Deadly cancers, meanwhile, may grow so fast that early detection with PSA doesn’t help.
“Is there a kind of prostate cancer that needs to be cured and can be cured?” said Brawley, who also wrote a commentary that appeared in Annals. “We still don’t have an answer to that.”
The best data on PSA screening come from two large clinical trials that tracked men for about 10 years. One showed no survival advantage. The other showed a slight one.
The Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial enrolled 76,693 men ages 55 to 74. One group received annual PSA tests and digital rectal exams from the trial research team; the other did not. A blood PSA level of 4 micrograms per liter was deemed suspicious.
There was no statistically significant difference in deaths from prostate cancer between the two groups.
The European Randomized Study of Screening for Prostate Cancer enrolled 182,160 men ages 50 to 74. One group received PSA testing, usually every four years, and the other didn’t.
The prostate cancer death rate was the same in both groups when the entire population was considered. In a subset of men between the ages of 55 to 69 in Sweden and the Netherlands, there was one fewer prostate cancer death per 1,000 men screened in the group that had PSA tests.
Neither study was perfect. In the U.S. study, many men in the nonscreening group received PSA tests anyway, which made the advantages of screening appear less than they actually are, Catalona said.
The European study had flaws too, Moyer said. Men not receiving PSA tests were treated in community hospitals when a cancer was detected, whereas those who were screened went to higher-quality university hospitals. This would overstate the advantages of screening.
The new recommendations, which extend ones from 2008 that advised against PSA screens for men over 75, were released in draft form in October. Since then, the task force has reviewed almost 3,000 public comments.
Many passionately defended men’s right to the test. Others wanted to know what the science had to say about men at above-average risk, such as those with family histories or African Americans.
The final document stated that there was no evidence that high-risk groups benefited any more from the test than anyone else.
Dr. Mark Litwin, chairman of urology at UCLA, said refinements to the PSA test or the discovery of new biological markers could make screening more effective. For now, he said, the key problem with PSA screening is that doctors and patients tend to treat every cancer aggressively when often close monitoring would be enough.
“It is a natural response to want to avoid risk of death,” he said. “To avoid risk of death from prostate cancer, men tend to be treated.”
Times staff writer Eryn Brown contributed to this report.