Assessing the potential benefits and harms of screening for prostate cancer using the prostate specific antigen (PSA) test, the Canadian Task Force on Preventive Health Care (CTFPHC) recently recommended against this type of screening.
"Unfortunately the PSA test is simply not an effective screening tool," Neil Bell, MD, CTFPHC member and chair of the working group for this guideline, said in a prepared statement. "Almost 20% of men aged 55 to 69 have at least one false positive; approximately 17% of them will have unnecessary biopsies.”
Also, more than half of the detected cancers are overdiagnosed, “which is the detection of cancers that would not have caused symptoms or death during the lifetime of the patient,” Bell explained. This can lead to unnecessary treatments, which can cause potential harms, such as impotence, incontinence, or infections. “Considering PSA screening results in only a 0.1% reduction in death from prostate cancer, the harms associated with screening outweigh the benefits for most people," Bell said.
Specifically, the guideline says:
- CTFPHC strongly recommends against PSA screening for men younger than 55 or older than 70 because there is no evidence that such testing reduces mortality. There is also evidence of potential harm.
- The task force doesn’t recommend PSA screening for men age 55-69 because there is “inconsistent evidence of small potential benefit of screening, and evidence of harms.”
PSA screening for prostate cancer is a controversial topic worldwide, and the release of the CTFPHC guideline brought it back to the forefront in Canada. "This isn't a black and white issue," says Stuart Edmonds, MD, vice president of research and health promotion and survivorship at Prostate Cancer Canada, which offers and funds public education, advocacy and research programs involving prevention, detection, treatment, and cure of prostate cancer. "You can't abandon testing when there's research out there that says it's useful, particularly in the absence of anything better. We believe that when the results are properly interpreted, the benefits of PSA screening outweigh the risks of not screening."
Similarly, the Canadian Urological Association (CUA) also does not support CTFPHC’s recommendation. “CUA continues to support selective PSA screening,” the organization said in a prepared statement. “CUA recommends a shared decision making process where healthy men with a good life expectancy should have the choice to be tested and not be dissuaded from doing so.”
CUA plans to release its own updated prostate cancer screening guidelines in 2015. In the meanwhile, CUA says that “in the absence of broadly accessible alternatives to the PSA test for prostate cancer screening, dismissing PSA testing would achieve a great disservice to Canadian men,” according to the statement. “PSA screening has been shown to decrease metastatic disease and prostate cancer-related deaths and save lives.”