The Problem With PSA
Julian Whitaker, MD
Fifteen years ago, I predicted “…the PSA test will funnel hundreds of thousands of men into prostate surgery, radiation, and chemotherapy—treatments that have not been proven to be any better than simply leaving the prostate cancer patient alone.”
That warning has been borne out over the years, and conventional physicians are finally beginning to realize it.
Moderate PSA Scores “Clinically Useless”
A study conducted by researchers at Stanford University School of Medicine and published in the Journal of Urology clearly shows that PSA testing is an unreliable indicator of prostate cancer risk. According to this study, PSA scores between 2 and 9 are “clinically useless” in determining the size or severity of a tumor.
To reach these conclusions the Stanford team examined the prostates of 875 men who had them removed over a period of 13 years. After comparing preoperative PSA scores with actual postoperative tumor size, the researchers found that for scores between 2 and 9, only 14 percent of the tumors correlated with their PSA values. In other words, a PSA score of 9 was no more predictive of a large, aggressive tumor than a score of 2. “It is random,” said lead researcher Thomas Stamey, MD. “I could get 15 percent by flipping a coin.”
Furthermore, PSA scores in this middle range were found to be of only “limited” value at predicting cure rates from surgery. Surgery was no more likely to save a patient with a PSA score of 2 or 3 than one with a score of 8 or 9.
What Is PSA?
So why the disparity between PSA values and actual cancer risk? Prostate-specific antigen is produced by prostate cells, and the PSA test measures the amount of this antigen in the blood. (PSA levels of 0 to 4 are considered to be normal, 4 to 10 moderately elevated, and over 10 high.)
It’s important to keep in mind that PSA is produced not only by cancerous tissues, but by benign tissues as well. Both prostatitis and benign prostatic hyperplasia (BPH) can cause PSA scores to rise. In addition, PSA levels are influenced in part by the size and weight of the prostate, which differs even among healthy men.
Although widespread PSA testing has increased the diagnosis and treatment of prostate cancer, it has done little to lower the death rate. In the 1990s when PSA testing became common in the US, the incidence of prostate cancer skyrocketed. In Britain, where PSA screening is much less common, the incidence went up only slightly. Nevertheless, the death rates from prostate cancer in both countries have been virtually identical for the last 30 years.
This means that doctors are diagnosing disease in essentially healthy patients. Worse still, they are then treating those patients with therapies that cause disability, impotence, and incontinence.
Take a Conservative Approach
I don’t mean to imply that prostate cancer is rare. It is the most common cancer in men. However, even when cancer is present, surgery, radiation, and chemotherapy are not necessarily the best course of action. Prostate cancers usually grow very slowly. As you have heard me say before, most men die with prostate cancer, not from it.
The bottom line is that blood tests cannot detect prostate cancer at an early stage. And as Dr. Stamey points out, biopsies cannot distinguish between aggressive tumors and “small cancers that will never bother a patient if they live to the age of Methuselah.”
- Stamey TA et al. Preoperative serum prostate specific antigen levels between 2 and 22 ng./ml. correlate poorly with post-radical prostatectomy cancer morphology. J Urol 2002. 167(1):103-11.
- Stamey, TA et al. The prostate specific antigen era in the United States is over for prostate cancer: what happened in the last 20 years? J Urology. 2004 Oct;172(4):1297-1301.
Modified from Health & Healing with permission from Healthy Directions, LLC. Photocopying, reproduction, or quotation strictly prohibited without written permission from the publisher. To subscribe to Health & Healing, click here.