Friday, October 7, 2011

PSA test gets a "D" from U.S. Task Force

By Elizabeth Cohen, CNN website, October 6, 2011
The U.S. Preventive Services Task Force, the group that told women in their 40s that they don't need mammograms, will soon recommend that men not get screened for prostate cancer, according to a source privy to the task force deliberations.

The task force is set to recommend a "D" rating for prostate specific antigen, or PSA, testing. Such a rating means "there is moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits," according to the group's website. The task force is set to propose this recommendation Tuesday, and then allow for a comment period before issuing a final recommendation.
According to a draft copy of a report scheduled to be released Monday, a review of studies shows screening with the PSA blood test results in "small or no reduction" in prostate cancer deaths.
The report adds that PSA testing is "associated with harms related to subsequent evaluation and treatments."
The PSA test, which is sometimes accompanied by a digital rectal exam, can help determine if a man has prostate cancer. The problem is that many of the cancers that get detected are so small and slow-growing, they'll never be harmful, and doctors have a difficult time discerning the quick, harmful cancers from the slow, harmless ones.
If you test 100 men over age 50, 17 of them will have prostate cancer, and only three of those will have a fast-growing cancer and die of the disease, according to Dr. Kenneth Lin, senior author of the paper due to be released Monday.
If the 14 men with the slow-growing cancers are treated, they could be rendered impotent or incontinent from the treatment; or worse, the treatment could kill them. About one in 500 men who has a radical prostatectomy will die because of complications of the surgery, according to Lin.
Some prostate cancer patients were disappointed with the task force's decision.
A spokesman for the Prostate Cancer Foundation called the proposed recommendation "a tremendous mistake."
"You're talking to someone whose life was saved by [the PSA test]," Dan Zenka said.
Being unable to discern the fast-growing from the slow-growing cancers is a serious problem, especially for a medical profession that wants to intervene to "make it better". Potentially being rendered impotent or incontinent by the treatment is also a serious problem. Sometimes, perhaps rarely, not knowing the results of a test like the PSA, can be a positive form of denial, since not knowing permits the patient to continue life as he has known it, if and until some of the ambiguity and uncertainty and potentially negative "side-effects" are reduced or eliminated.
Another issue this report points to is the "relative" stature of most medicine. It is a process of continuous discovery, some of the new discoveries supplanting old practices, leaving many patients confused, uncertain and sceptical of not only "first opinions" but also of some invasive treatments.
However, healthy scepticism in patients requires relatively easy access to "second opinions" and, at least in Canada, accessing those second opinions is not always easy. I recall a conversation my then spouse had with an otolaryngologist, following a surgery he performed on our then three-year-old daughter, including a mastoidectomy, a very rare procedure in the mid-seventies. She simply asked, "Could our daughter be suffering from allergies?"
The doctor snapped, "We treat ears here! and dismissed the legitimate inquiry. Only after pleading with our family doctor did we secure a referral to Sick Kids Hospital in Toronto, where, indeed, multiple allergies were found, and treated. Today that daughter is a healthy forty-something, fully engaged in teaching high school students in her second language.
When I confronted that same family doctor about the risks of the PSA, and my refusal to undergo the test, in 2001, he was shocked, and even a little dismayed that I would question the test. My reading included evidence from medical experts about the relative risks involved, and we had to agree to disagree.
There are indeed times when the medical profession does not know what to do with information it may have gathered from some of its diagnostic procedures, and the patient, finally, is the arbiter of what procedures are performed on his/her body. And just like ensuring that the civilians are always in charge of the military, so should the patient be the final decision-maker in the maze of recommended options from the medical fraternity.
And when the evidence of over-prescribing medications whose side-effects seem to outweigh the benefits, one has to wonder if moderation in medicine would not be an advancement that both the profession and it clients would do well to incorporate into the training.

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