Doctors disagree on when to stop PSA screening
Last Updated: 2012-05-28 10:00:17 -0400 (Reuters Health)
By Amy Norton
NEW YORK (Reuters Health) - Doctors vary when it comes to deciding when an older man can stop routine PSA screening for prostate cancer, a new study finds.
In the U.S., many men now have their cancer diagnosed at an early stage through screening with prostate-specific antigen (PSA) blood tests.
Although that sounds like a good thing, PSA screening is controversial. On Monday, the U.S. Preventive Services Task Force (USPSTF) -- an expert panel advising the federal government -- recommended against routine screening for men at average risk of prostate cancer, regardless of their age (see Reuters story of May 21, 2012).
That's because prostate cancer is often slow-growing and may never progress far enough to threaten a man's life. So finding and treating early tumors can do more harm than good for some men, since treatment carries risks.
For elderly men in particular, the risks of surgery or other treatments are usually thought to outweigh any potential benefit. On top of that, a man's PSA levels often rise with age, or because of benign prostate enlargement -- so an elevated PSA level may lead to unnecessary biopsies.
For those reasons, the USPSTF has long recommended against routinely doing PSA screening in men age 75 and older.
But some other groups, including the American Cancer Society, have more liberal guidelines. Their recommendations say doctors should consider a man's age and his life expectancy -- because if an elderly man is healthy and could live for another decade or more, he might still benefit from PSA screening.
In the new study, researchers at Johns Hopkins School of Medicine in Baltimore looked at how primary care doctors in their university network typically handle the age question.
They found, not surprisingly, that practices varied. Of 125 doctors, about one-third said they had no particular age when they stopped recommending PSA screening.
Of the rest of the group, a little more than half stopped routinely screening patients at the age of 75, compared to 21 percent who stopped at age 80 or older and 27 percent at age 70 or younger.
When asked about the obstacles to stopping PSA screening, three-quarters of doctors said their patients "expect" to continue getting yearly PSA tests.
It's not fully clear how much of a barrier patients' expectations are, according to Dr. Craig E. Pollack, the lead researcher on the study.
"If you ask patients about screening, they'll often say they rely on their doctors' recommendations," Pollack said.
The message for older men, according to Pollack, is to have an open discussion with your doctor about whether it's time to stop PSA screening.
But the decision can be tricky. In this study, 59 percent of doctors said they take a man's age and life expectancy into account -- as recommended by the American Cancer Society and the American Urological Association.
But estimating life expectancy is tough, Pollack said. Two-thirds of doctors in the survey said it was "somewhat" to "very" difficult.
Going forward, Pollack said, it will be important to develop better "decision support" tools to help primary care doctors estimate men's life expectancy, and then discuss with their patients how life expectancy fits into PSA screening.
Of course, experts disagree about whether most men should even start PSA screening in the first place.
When the USPSTF came out with its recommendations Monday, critics charged that the advice will cost lives.
Supporters, though, said that stopping routine screening would prevent needless cases of incontinence and erectile dysfunction that can come from prostate cancer treatment.
And they pointed out that the task force advice does not mean men cannot have PSA screening -- but that they should decide with their own doctors what's best for them.
Exactly what impact the new USPSTF recommendations will have is unclear. A study published last month found that although the task force has long advised against PSA screening for men age 75 and up, doctors often do it anyway (see Reuters Health story of April 26, 2012).
Of nearly 15,000 elderly men surveyed in 2010, 60 percent said they'd had a PSA test in the past year.
And another study, published in the Journal of the American Medical Association, found that the percentage of older men getting PSA screening did not change after the USPSTF recommendation was published in 2008 (see Reuters Health story of April 25, 2012).
Before and after the guidelines came out, about 44 percent of older men said they'd had a PSA test recently.
Just over 28,000 U.S. men will die of prostate cancer this year, according to the American Cancer Society. But close to 242,000 new cases will be diagnosed.
According to the National Cancer Institute, about half of all U.S. men diagnosed with prostate cancer in 2009 fell into the "low-risk" category -- meaning their cancer was unlikely to progress.
SOURCE: http://bit.ly/KLnmUg Cancer, online April 19, 2012.