October 16, 2013
News Review From Harvard Medical School – Many Doctors Ignore PSA Screening Guidelines
Many doctors are ignoring guidelines to steer clear of PSA testing for older men, says a study. Researchers from the University of Texas Medical Branch in Galveston reviewed Medicare records for more than 61,000 patients and more than 2,000 doctors. More than 40% of men ages 75 and older had prostate-specific antigen (PSA) blood tests, which screen for prostate cancer. None of these men had a history of prostate cancer. The researchers found that certain doctors ordered the test more than 10 times as often as other doctors did. The PSA test is not recommended for men ages 75 and older, because most prostate cancers grow so slowly that men this age would die of another cause before the cancer became a threat. The researchers also note that diagnosis and treatment of prostate cancer in elderly men can carry health risks. The study was published in the October 16 issue of the Journal of the American Medical Association.
By Howard Lewine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
The United States Preventive Services Task Force (USPSTF) recommends against routine screening for prostate cancer, no matter the age of a man. Most other medical organizations suggest that men between the ages of 50 and 75 have a discussion with their doctor about the pros and cons of routine screening.
No medical organization recommends screening men after age 75. Despite this very clear message, many doctors still were still doing it in 2010. Those results are reported in today’s Journal of the American Medical Association.
The test used to screen for prostate cancer is a blood test for prostate-specific antigen (PSA). PSA is a highly sensitive test: It identifies nearly all men with prostate cancer. However, it is not very specific: The PSA test also comes back positive for many men who do not have cancer.
Men with enlarged prostate glands or inflamed glands often have high PSA levels. And when prostate cancer is causing the high PSA level, the cancer usually is growing slowly. These slow-growing cancers usually don’t shorten a man’s life. And if he does have symptoms, medicine can often be enough.
It’s not that the USPSTF and other medical organizations are against any type of screening for prostate cancer. It’s just that PSA is a very poor screening test.
Men over 75 are more likely to be harmed by the test than helped. The PSA blood test itself is not harmful. The harm comes because a high level tends to lead to a prostate biopsy. If the biopsy shows cancer, a man must decide: Should he wait to see what happens over time, or start treatment immediately?
Not treating prostate cancer can cause worry and anxiety, even if it is the slow-growing type. On the other hand, treatment may lead to erectile dysfunction, incontinence or other side effects, without extending a man’s lifespan.
What Changes Can I Make Now?
Men over 75 should not be offered a PSA blood test without evidence that it will do more good than harm.
Should an older man in good health who wants the test be denied it, even if he understands that the risks are greater than the benefits?
I would have the same conversation that I do with men age 50 to 75. I would say: Ask yourself these questions before having your blood drawn for a PSA test.
- Am I willing to proceed with a prostate biopsy if PSA testing indicates that I might have prostate cancer?
- Would I want to get treatment right away if the biopsy shows any cancer cells, even very low-grade cancer cells?
If a man answers "yes" to both of those questions, then getting a PSA test is a reasonable choice.
If he answers "yes" to question 1 and "no" or "not sure" to question 2, then he must ask himself:
- Would I be comfortable with periodic monitoring but no therapy, if the biopsy shows only low-grade prostate cancer? (Frequent monitoring would include regular PSA blood tests and perhaps repeat prostate biopsies.)
What Can I Expect Looking to the Future?
There will be a better prostate cancer screening strategy in the future. It will more accurately predict which men do need aggressive therapy to cure a potentially life-threatening condition. Meanwhile, doctors need to be straightforward with their male patients about the limitations of PSA screening.