A substantial number of elderly men are getting screened for prostate cancer unnecessarily, researchers from the San Francisco VA Medical Center report in JAMA (2006;296:2336–2342).
In their cohort study of nearly 600,000 men aged 70 and older at dozens of VA hospitals in the United States, they found high rates of Prostate-Specific Antigen (PSA) testing, even among elderly men with multiple comorbidities whose life expectancy was substantially less than 10 years. Men with a history of prostate cancer, elevated PSA, or symptoms of the disease were excluded from the analysis.
The balance of benefit to harm associated with early detection and treatment of prostate cancer shifts substantially with age and comorbidity. The complications and side effects of treatment generally occur immediately or within a couple of years, but the benefits to survival become significant many years later. For this reason, organizations such as the American Cancer Society (ACS) and the American Urological Association do not recommend that testing be considered for men with a life expectancy less than 10 years. The ACS recommends health professionals discuss the risks and benefits of yearly screening beginning at age 50 (or younger, for men at high risk of the disease) with men with at least a 10-year life expectancy.
The study findings suggest many men are being subjected to unnecessary harm from anxiety about test results, unneeded diagnostic procedures, and potential side effects of prostate cancer treatment, said lead researcher Louise C. Walter, MD, a Staff Physician at the San Francisco VA Medical Center and Assistant Professor of Medicine at the University of California, San Francisco.
“I've seen it happen to my patients,” explained Walter, a geriatrician. “They get very worried and get procedures done to them that leave them incontinent and impotent for a disease that I thought wasn't going to cause them major problems.”
Other experts agree the findings are cause for concern.
“There have been at least three risk-benefit analyses suggesting we probably do cause more harm than benefit [with PSA screening] after age 70 or 75, based on morbidities of early intervention, and that's not inconsequential,” said Andrew Wolf, MD, Associate Professor of Medicine at the University of Virginia Health System and a member of the ACS Primary Care Advisory Committee.
“There's a good chance a lot of these men are being harmed,” added Wolf, who was not involved in the study.
The study found that, overall, 56% of elderly men in the cohort had PSA testing done. PSA testing rates did decrease with age, but not as much as expected. The PSA testing prevalence for men aged 85 or older was 36%, but the authors note that fewer than 10% of men this age live 10 or more years. Surprisingly, prevalence of testing was not associated with comorbidity, as assessed by the Charlson Comorbidity Index, a summary measure of 19 chronic diseases previously found to be associated with mortality. Among men aged 85 and older, 34% of those in “best health” (Charlson score 0) got PSA tests, compared with 36% of those in “worst health” (Charlson score 4 or higher).
Overzealous screening can distract clinicians' and patients' attention from more pressing medical concerns, such as dementia, congestive heart failure, dialysis, oxygen dependency, and functional limitations, Walter noted.
“You put any of those [conditions] with [age] 85 and above, and you do wonder why you'd be getting a PSA test,” she said.
Better guidance for estimating life expectancy could help physicians avoid unnecessary prostate cancer testing, she added.
Physicians need to have frank discussions with elderly men about the pros and cons of prostate cancer screening, Walter and Wolf agree.
Some men will choose to be tested, regardless of the risks, Walter acknowledged. When that happens, “I do make sure they understand that there are downsides and that it's not just a blood test,” she said.