Guidelines limiting PSA screening for prostate cancer detection in older men are widely ignored, researchers said Tuesday, and physicians seem likely to continue to ignore them. Nearly half of all men age 75 and older receive the PSA test from doctors, despite a growing body of evidence that the tests do more harm than good, according to Dr. Scott E. Eggener of the University of Chicago Medical Center. The issue has been in the news lately with the report last week that 81-year-old Warren Buffett, the well-known entrepreneur, was diagnosed with stage 1 prostate cancer and would begin receiving radiation treatment for it. Because stage 1 prostate cancer is very slow-growing, an elderly man is more likely to die of some other cause before the tumor gets large enough to do any damage. Critics thus charged that Buffett should never have had a PSA test in the first place, that he definitely should not have had a biopsy for a slightly elevated PSA level, and that he should not have been treated. All three actions, critics said, are a waste of medical resources.
In August 2008, the U.S. Preventive Services Task Force, which issues recommendations that are generally followed by Medicare and many insurers, said that men over the age of 75 should not receive the prostate specific antigen (PSA) test, which measures blood levels of a protein secreted by the prostate gland. In younger men, elevated levels are usually a sign that a biopsy needs to be performed. But because most prostate cancers are very slow growing -- 80% of men over the age of 80 have them with no apparent harm -- such testing is not advisable in older men. The task force noted that “there is moderate or high certainty the service has no net benefit or that the harm outweighs the benefits.” Side effects from treatment of a prostate tumor can include incontinence, impotence, rectal bleeding and many other complications.
Eggener and his colleagues used data from the 2005 and 2010 National Health Interview Surveys, in which a representative sample of the U.S. population was interviewed. They reported Tuesday in the Journal of the American Medical Assn. that in 2005, before the recommendation was released, 43% of men over age 75 received the test. In 2010, two years after the new guidelines were released, the percentage had grown to 43.9%. In both years, the researchers excluded men who had a test because of a specific prostate complaint, restricting it only to those who received the test as part of routine screening. Only 12.5% of men in their 40s and 33.2% of men in their 50s -- both groups that could benefit much more greatly from early diagnosis and treatment -- received the test. Among men ages 60 to 74, 51.2% received the test. All the estimates were probably low, the authors noted, because self-reports are generally less accurate than data extracted from medical records.
In October 2011, the task force issued draft guidelines that recommend against PSA screening in all age groups.
In a separate study, Dr. Craig E. Pollack of the Johns Hopkins Bloomberg School of Public Health in Baltimore and his colleagues distributed questionnaires to physicians in the Johns Hopkins Community Physicians group, which each year sees about 40,000 men eligible for PSA screening. Although the vast majority of the physicians were familiar with the draft guidelines, the team reported Monday in the Archives of Internal Medicine, only half agreed or strongly agreed with them. Only 1.8% of the physicians said they would no longer order PSA tests, 37.7% said they would not change their screening practices, and the rest said they had not decided. “These results suggest that, if finalized, the USPSTF recommendations may encounter significant barriers to adoption.”