Tuesday, September 1, 2009
Prostate Cancer Overdiagnosis
One of the hardest things to explain to patients is the whole deal about overdiagnosis of prostate cancer in men. More than 1 million men in the U.S. have been diagnosed with and treated for prostate cancer since that test has been used. That would be good news, except for the fact that the "vast majority of these 1 million men did not benefit from early detection," according to a new study published in the Journal of the National Cancer Institute.
The bottom line is that screening for prostate cancer is of questionable benefit. Another 2009 study published in the New England J of Medicine, had the same findings...that screening for prostate cancer did not provide a mortality benefit. An elevated PSA is not specific for cancer and a significant number of men with PSA values under 4 have prostate cancer. It is not a very good test and tumors can be slow growing and of no health significance.
To add to the confusion, the American Urological Association (Society of Urologists) issued guidelines that PSA screening should begin in healthy men at age 40. Keep in mind that Urologists benefit greatly when men with elevated PSAs need imaging studies and biopsies. It is these invasive procedures that are considered "over treatment" in the other studies.
The US Preventive Services Task Force has concluded that the evidence is insufficient to make a recommendation for or against routine screening using PSA testing or digital rectal examinations. The US Preventive Services Task Force cites the current lack of evidence that early detection improves health outcomes and the potential harm that can result from treatment.
With these divergent opinions from major credible scientific organizations, you can see that this is very muddy water. Those of us who are in the trenches, taking care of patients, are left to try and explain the current science to men (impossible) and to make our best judgment about screening tests.
I do it, but I am less than comfortable with the results.
Posted by Toni Brayer, MD at 8:47 PM