Medical journal reports that PSA screening tests for prostate cancer cause more harm than good
A U.S. group that evaluates medical screenings has recommended against PSA-based tests for all men, regardless of their age.
These blood tests, which measure the level of a prostate-specific antigen, are commonly used to detect the existence of prostate cancer.
Today in the online version of the peer-reviewed Annals of Internal Medicine, the United States Preventive Task Force gives the PSA test a "grade D recommendation", saying that the harm of testing outweighs any benefits.
The task force based its conclusion on two major trials in asymptomatic men.
The first in the U.S. did not demonstrate any reduction in cancer mortality from the tests. The other trial, which took place in seven European countries, found a reduction of one death per 1,000 men screened in two of the countries involving a subgroup of men between 55 and 69.
"Strong evidence shows that PSA screening is associated with significant harms," the USPSTF stated. "Nearly 90 percent of men with PSA-detected prostate cancer undergo early treatment with surgery, radiation, or androgen deprivation therapy. Evidence shows that up to five in 1,000 men will die within one month of prostate cancer surgery and between 10 and 70 men will survive, but suffer life-long adverse effects such urinary incontinence, erectile dysfunction, and bowel dysfunction."
In a new book called Seeking Sickness: Medical Screening and the Misguided Hunt for Disease (Douglas & McIntyre), University of Victoria pharmaceutical-policy researcher Alan Cassels raises serious concerns about PSA testing.
"Whether we like it or not, urologists have an unavoidable conflict of interest regarding PSA screening because if so much of their work depends on treating prostate cancer when they see it, it is hard for them to be critical of PSA testing," Cassels writes. "In fact, asking a urologist if you need a PSA test or if you need surgery to treat what a biopsy has found might be like asking your barber if you need a haircut. You are asking the right question of the wrong person."
He points out in the book that men whose prostate cancers are revealed through these diagnostic examinations do not live longer than those whose cancers were discovered in other ways.
"The fact that one of the biggest organizations in the U.S. that advises on screening is giving a major thumbs down to one of the most popular forms of cancer screening—this is a pretty big deal," Cassels told the Straight by phone. "It's been in the works for a long time. I totally agree with it because they're finally recognizing that when you quantify the benefits and the harms, you're helping very few men by screening them for prostate cancer."
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