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Intent/Governance affecting more than 1 eCQM
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Resolution: Unresolved
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Minor
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None
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Nelson N. Stone
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The Icahn School of Medicine at Mount Sinai
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PSA test for early diagnosis of prostate cancer
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Comment - PSA Screening
PSA was introduced in the late 1980's when most prostate cancers were large. The standard detection method at the time was digital rectal exam (DRE). Most men had their prostate cancers detected when they had advanced local disease. PSA, because it was a simple blood test, afforded men the opportunity to have a simple test to look for early prostate cancer. Over the ensuing 15 years the death rate from prostate cancer dropped 40% as a direct result of PSA testing. Compare this to a country like Japan. Autopsy studies demonstrate the incidence of prostate cancer is the same in Japanese men as Americans. Yet there are far fewer men diagnosed with prostate cancer (about 50,000 in a country of 100 M) because PSA is only used in 5-10% of the male population. In contrast to the US, Japanese males are diagnosed with more advanced disease and the death rate from prostate cancer continues to increase. This is exactly why there is a difference in the European and US screening studies. In Europe, fewer men had a PSA test before study entry compared to US men, where over 50% had a prior study entry. In the US population, finding a survival benefit would obviously prove difficult because we have used PSA as an early detection test for so long and with such great success. In essence the US studies proved that PSA has saved lives.
The USPTF also states that PSA causes "more harm than good". This is an unfortunate byproduct of the success of PSA. However, the problem is not PSA but the biopsy technique used to diagnosis prostate cancer. The TRUS biopsy, coincidentally, was also introduced at the same time as PSA. This technique, which requires puncture of the anterior rectal wall to get a prostate sample, worked well when prostate cancers were large, like they were back in the early 1990s. As a direct result of the success of PSA testing, cancers have become much smaller (but no less deadly as the number of high grade lethal cancers has not decreased) and harder correctly identify. Often times a TRUS biopsy finds a low grade cancer suggesting patients can be safely observed (no active treatment) but when the same patient is subject to prostatectomy 30% have potentially lethal disease. On the flip side, if patient and physician opt to remove the gland just to be sure, then 50% end up having unnecessary surgery. No wonder why the USPTF says PSA does more harm than good.
The solution to this problem, is not to restrict PSA and send us back to the pre-1980s, but to improve the biopsy test. Investigators are having success using new MRI technology to better select high risk patients for biopsy. Mapping biopsy through a transperineal approach correctly identifies which patients should have surgery or radiation or which can be safely watched.
Investigators using these technologies, both in the US and Europe have published their data which needs to be incorporated in the decision on how to best use PSA. The USPTF approach is outdated, short-sited and dangerous.
Respectfully submitted,
Nelson N. Stone
Professor of Urology and Radiation Oncology
The Icahn School of Medicine at Mount Sinai