Lowering PSA Threshold to 2.6 Is Sound Practice
Much publicity has been given to a new study suggesting that biopsies should be recommended for men whose PSA tests 2.6 or higher. (We introduced the study in the Fall 2003 QUEST and cover it extensively in this Winter 2003 issue.)
Previous protocol called for a biopsy with a PSA reading of 4.
Critics of lowering the PSA Threshold for biopsy from 4 to 2.6 suggest the practice would double the number of biopsies without significantly affecting the numbers of prostate cancers requiring treatment.
I respectfully disagree.
Most men with PSA test results in the 2.6 to 4 range will eventually reach the 4.0 threshold.
When we did our cancer screening study in St. Louis, we saw PSA rising in many men, but we could not recommend biopsy until it reached 4ng/ml, because that was the approved protocol.
Then it would reach 4, and we would do a biopsy and find cancer and do a radical prostatectomy, and in 30% of the men, the cancer had extended to the edge of the prostate or beyond.
Those men would become very upset because the writing was clearly on the wall earlier, but we could do nothing because of the higher threshold.
In 1995, I examined my screening data and found that in about half of the men with PSA results between 2.6 and 4, the levels rose to above 4 within four years.
Critics say we’re going to be doing more biopsies with the lower threshold, but most of the men will have biopsies anyway at a later date. And the benefit to patients to do them earlier speaks out clearly in our study.
So we’re not doubling the number of biopsies with this recommendation. We’re simply doing the same biopsies a bit earlier in life.
Our study also showed that lowering the threshold to 2.6 in men under 60 may double the cancer-detection rate without significantly altering the number of false-positive results.
I was disappointed in the way this study was reported in the lay press. Some of the headlines in the popular media suggested that the PSA test isn’t good because it misses so many cancers, and that was not the message of the study.
The message of our study is that the PSA test is not being used as effectively as it could be and that the PSA test would be much more efficient with the lower threshold.
The most important message from the study to urologists is if the PSA is higher than 2.6, that patient should seriously consider having a biopsy, regardless of age.
And if the patient decides after giving it serious consideration to not have it, then he should have the PSA monitored every three to six months to see if it is rising.
(The study recommending the lowering of the PSA Threshold to 2.6 from 4 was authored by Dr. Rinaa Punglia, of Harvard University, and co-authored by Dr. Catalona. It was published in the July 24, 2003 issue of the New England Journal of Medicine.)