Thursday, April 13, 2017

Updated Prostate Cancer Screening Guidelines

Just five years ago the U.S. Preventive Services Task Force (USPSTF) recommended that men 55-69 should be "discouraged" from having the PSA test to screen for prostate cancer (see this blog, May 27, 2012). At the time, the best evidence was that the risks of having a PSA test slightly outweighed the rewards. That's because the PSA test is not 100% accurate; sometimes it gives false positive results, meaning that the test indicates that prostate cancer might be present when in fact it isn't. According to the USPSTF, these false positive PSA tests were leading to biopsies (the next step in making a diagnosis), radiation, and sometimes even to surgeries for prostate removal, all of which carry some risk.

But just recently the USPSTF reversed course; now it recommends that men aged 55-69 should "have a conversation with their doctor" about the advisability of having the PSA blood test to screen for prostate cancer. Why the apparent about-face? Again, it's based on the best available evidence. The PSA test hasn't gotten any more reliable, but what has changed is what happens after a positive test result. Recent research has showed early, aggressive treatment after a positive PSA test isn't necessary and doesn't increase patient survival. That means that doctors can afford to wait, doing repeated PSA tests for years if necessary before recommending biopsies or treatment. As a result, the risks of having the PSA test (and everything that comes after) have declined to the point that the rewards now slightly outweigh the risks.

As before, the PSA test is not recommended for men over 70 (they're likely to die of something else before they would die of a slow-growing prostate cancer) or for men under 50 (prostate cancer is too rare in younger men for the test to be of much benefit).

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