GALVESTON, Texas - Many primary care doctors continue to administer the prostate-specific antigen test to even their oldest patients despite the fact that no medical organization recommends prostate cancer screening for men older than 75, according to new research from the University of Texas Medical Branch at Galveston.
In a research letter published in the Journal of the American Medical Association, UTMB researchers found a high variability in standard PSA-ordering practice among primary care physicians. Some doctors ordered the test for their older male patients regularly, despite more than a decade of recommendations against doing so. The doctors' tendency to order the test had little to do with measurable patient characteristics.
"Our results suggest that a major reason for the continued high PSA rate is decision-making by the physicians," said senior author Dr. James Goodwin, director of UTMB's Sealy Center on Aging. "That's why there was so much variation among physicians, after accounting for differences among patients. It is clear that some of the overuse is because of preferences of individual patients, but the conclusion of our results is that much more is coming from their primary care physicians."
The purpose of UTMB study was to determine the role primary care physicians play in whether a man receives PSA screening. The study looked at the complete Medicare Part A and Part B data for 1,963 Texas physicians who had at least 20 men age 75 or older in their panels and who saw a man three or more times in 2009. Of the 61,351 patient records examined, 41 percent of men received a PSA screening that year, and 29 percent received a screening ordered by their primary care physician.
Which primary care physician a man sees explained approximately seven times more of the variance in PSA screening than did the measurable patient characteristics, such as age, ethnicity, and location, according to the study.
"Overtesting can create harms, including overdiagnosis," said Dr. Elizabeth Jaramillo, lead author and an instructor of internal medicine-geriatrics at UTMB. "The vast majority of prostate cancers are so slow growing that an elderly man is much more likely to die of another condition in his lifetime than from the cancer."
Additional research is needed to understand why some primary care physicians order PSA screenings more often than others. The study suggests that overtesting rates be included as quality measures of PCPs. Medicare data can be used to generate such measures.
Co-authors include biostatistician Alai Tan, research associate Liu Yang and professor Yong-Fang Kuo. The research was supported by the Cancer Prevention Research Institute of Texas, the National Institutes of Health, the Agency for Healthcare Research and Quality and the UTMB Clinical and Translational Science Award.
Routine prostate cancer screening for asymptomatic patients -- especially older ones -- has been criticized by many organizations over the past dozen years. The American Cancer Society, the American Academy of Family Physicians and the American College of Physicians have all called for curtailing routine annual PSA testing because it so often leads to unnecessarily aggressive treatment that can cause impotence and incontinence.
The screening test detects the presence of PSA, a protein produced by the prostate gland. Traditional thinking was that the higher a man's PSA level, the more likely he was to have prostate cancer. New evidence shows that many factors can increase a man's PSA level, and that even if cancer is one of those factors, most prostate cancer is so slow growing it will never progress to a dangerous level.
According to a 2012 study by the National Cancer Institute, a 13-year cancer screening trial showed that men who undergo annual PSA screening have roughly the same death rate from prostate cancer as men who don't.
The U.S. Preventive Services Task Force called for the elimination of routine PSA screening in 2012. In May the American Urological Association said routine PSA screening should be limited to men between 55 and 69.
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ABOUT UTMB HEALTH: Texas' first academic health center opened its doors in 1891 and today comprises four health sciences schools, three institutes for advanced study, a research enterprise that includes one of only two national laboratories dedicated to the safe study of infectious threats to human health, and a health system offering a full range of primary and specialized medical services throughout Galveston County and the Texas Gulf Coast region. UTMB Health is a component of the University of Texas System and a member of the Texas Medical Center.