A new study finds that too many doctors ignore current guidelines that advise against giving PSA tests to elderly men, subjecting many of these patients to needless worry and bother.
Even though no major medical group currently recommends prostate-specific antigen (PSA) blood tests for men older than 75, more than 40 percent of the men covered in the new study were still being screened for prostate cancer in this way.
"Depending on which primary-care physician a man sees, he will be up to seven times more likely to receive the test than if he had seen a different primary-care physician," said lead researcher Elizabeth Jaramillo, M.D., from the department of geriatrics at the Sealy Center on Aging at the University of Texas Medical Branch in Galveston.
The findings, published in the Journal of the American Medical Association, are based on Medicare records for more than 61,000 patients and close to 2,000 primary-care doctors.
PSA testing is generally not recommended for men aged 75 and older because 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, Dr. Jaramillo said.
"When used in elderly men, the PSA test can lead to harms, including overdiagnosis," she said. "Overdiagnosis is when someone who will live for a long period of time will get diagnosed and treated for a condition that normally would never cause symptoms or be detected in their lifetime."
The treatment, perhaps including surgery, can be riskier than the disease and cause significant emotional stress. "We do not need to be screening elderly men for prostate cancer," Dr. Jaramillo said.
It is estimated that more than 1 million excess prostate cancers have been identified from PSA testing, Dr. Jaramillo said.
At least one other expert disagreed with Dr. Jaramillo on the screening of elderly men, however.
Anthony D'Amico, M.D., chief of radiation oncology at Brigham and Women's Hospital in Boston, said he thinks screening decisions should be based on a man's overall health and life expectancy, not his age.
"According to the study, in patients with no [other illnesses] there is more PSA testing, which would be very reasonable, because people who are in the best health for their age actually live longer than people of that age in general," he said.
Dr. D'Amico said these data need to be parsed further to see if doctors were testing all men or only those who were otherwise healthy.
Although there is no proof that testing men 75 and older is beneficial, Dr. D'Amico said, it may be worthwhile for some men. "My personal opinion is in men over the age of 75 who are healthy, particularly those at high risk, it's very reasonable," he said.
For the study, Dr. Jaramillo's team used Medicare data to determine the rate of PSA screening among men 75 and older who had no history of prostate cancer. The researchers found that about 41 percent of the men received PSA screening and almost 29 percent received PSA screening ordered by their primary-care doctor. Both rates declined with patient age.
Whether a man was screened depended on which doctor he saw. The researchers uncovered a 10-fold difference in the rate between doctors who ordered the most tests and those who ordered the least.
In addition, which primary-care doctor a patient saw accounted for about seven times more of the variation in PSA screening than did patient characteristics, the researchers said.
Other than skin cancer, prostate cancer is the mot common cancer among men. According to the American Cancer Society, more than 238,000 new cases of prostate cancer will be diagnosed this year.