THROWING THE PSA OUT WITH THE BATH WATER
January 9th, 2012
Patients often ask me about my feelings about the news reports regarding PSA. Some patients are reluctant to have PSA drawn and many are confused. I can start by telling you that I agree with the impetus behind the controversy as PSA has been used incorrectly, has been misinterpreted and even abused. My response is that PSA is like an artist’s paint brush in that it’s just a tool. In the right hands it can help create beauty and art, but in the unskilled hands it is useless. Similarly, PSA is a tool and its usefulness and interpretation is highly nuanced. If not used properly it is not only ineffective but can lead to incorrect interpretations and unnecessary procedures.
Here is some information about PSA
• PSA is the most valuable cancer marker of all cancers. While PSA is only useful for prostate cancer, there are no other cancers for which there is a marker anywhere near as reliable, easy to use and specific as PSA is to prostate cancer.
• We would all like to have a prostate screening test that works like a pregnancy test. If it turns black you have cancer and if it turns white you don’t. Such a test does not exist for prostate or any other cancer. In fact, PSA as a screening test is now less focused on absolute cut-off of 4.0 as normal or abnormal. We are now looking more at PSA trends over the course of years, PSA corrected for prostate volume and fractionated PSA (free and complexed PSA). Also there are other tools such as PCA3 a urinary tumor marker that we are using in combination. Thus, PSA is only one tool of many that we have available to determine ones risk of prostate cancer.
• PSA came into popular use as a tool for prostate cancer around 1990. Starting around 1994 the death rate due to prostate cancer has dropped dramatically. Nonetheless, prostate cancer is the second leading cause of cancer deaths in men.
• The controversy about PSA is solely limited to its use as a screening tool. Its usefulness as a tool to monitor existent prostate cancer is well established. So for someone who has or had prostate cancer, PSA is a very valuable indicator for knowing its current status or if it is growing back.
In summary, PSA is a very valuable tool in screening and monitoring of prostate cancer. But like a painters brush, it needs the right person behind it who knows how to use it and how to interpret it in context of other screening tools.
Eugene Dula, M.D., FACS