Debate intensifies over prostate specific antigen screening in older men

September 1, 2008

There are no high-level data to support current screening practices for PSA in men of any age, particularly in older men with a shorter life expectancy.

Key Points

Adding fuel to the fire, the U.S. Preventive Services Task Force recently recommended that men age 75 years and older and men under age 75 with chronic medical problems and a life expectancy of fewer than 10 years not be screened for prostate cancer (Ann Intern Med 2008; 149:185-91).

About a quarter of physicians recommend stopping PSA screening for patients between the ages of 76 and 80. Once patients pass the age of 80, 60% of physicians would prefer to halt PSA screening, reported Badrinath Konety, MD, associate professor of urology and epidemiology at the University of California, San Francisco, and chief of urology at the San Francisco Veterans Affairs Medical Center.

Medical logic suggests that PSA screening cease at the point at which successful detection of prostate cancer can no longer be expected to add to life expectancy for the typical man, Dr. Konety said. In the United States, that would suggest halting PSA screening at age 75. According to the U.S. Preventive Services Task Force, evidence suggests that the benefits of screening older men for prostate cancer are outweighed by the potential for substantial physical and psychological harm from screening.

But a second view suggests that PSA screening continue, regardless of advancing age. The rationale for old-age screening is that incidence of high-risk prostate cancer rises with advancing age, reaching 42% beyond the age of 75.

Dr. Konety reminded the symposium attendees that men with advanced disease are more likely to die of prostate cancer than of any underlying condition.

"I am not sure it would be practical or even possible to summarily stop screening in all men at age 75," Dr. Konety said. "We need to reassess the potential benefits of continuing PSA screening for elderly men on an individual basis, but we can't uniformly ban screening at a predetermined age."

The argument against screening holds that observation offers older men a chance of better quality of life than screening and invasive diagnostic follow-ups do.

PSA screening detects 95% of the relevant prostate cancers in men age 75 and older, Dr. Konety said, but it also has a 56% overdetection rate in the same population. That high rate of false positives leads to a significant number of unnecessary, uncomfortable, and costly diagnostic interventions and treatments.

What patients want

Men themselves want and expect PSA screening into old age. Only 9% of men age 85 or older can expect to live 10 years or longer, Dr. Konety said. However, 36% of men in that age group still undergo PSA screening. Among men between the ages of 85 and 100, 50% percent tell surveyors that they expect to undergo PSA screening soon.

There are also legal issues surrounding PSA screening. Twenty-seven states require Medicare and other insurers to cover PSA screening, regardless of patient age, according to Dr. Konety.

Primary care physicians also have emerged as key proponents of PSA screening into old age, he added. Recent surveys have found that nearly half of primary care practitioners recommend PSA screening for older patients. The reason most often cited is fear of a lawsuit for having provided less than the standard of care.

That standard of care may be clarified when two major screening studies now under way in the United States and Europe report data. Until then, Dr. Konety said, physicians and patients need to reassess the usefulness of PSA screening in older men.

"We need to remind men that an elevated PSA is not a death sentence," he said. "Finding an elevated PSA does not automatically mean cancer."