Prostate Cancer After Herbal Supplements
I received this email: “Stop scaring everybody. Tell us how to prevent prostate cancer.” This was in response to The Ghost of Larry Clark. In that piece, I described a selenium cancer prevention study and its aftermath. I concluded that we did not yet have scientific basis for prostate cancer prevention. I still hold this view.
Prevention comes in two varieties: things we can do to lower risk and things we can avoid to minimize risk. Selenium would fall into the former category. But there have always been suggestions of the latter, too. For example, we are told to avoid cadmium smelting and exposure to Agent Orange. Who do you know who smelts cadmium or bathes in Agent Orange, as some of my Veterans patients used to do? It’s good advice but it’s of little practical value.
Is there something we can avoid to which, unlike cadmium and Agent Orange, many men are exposed?
A report in Clinical Cancer Research tells the story of two Texas men who developed aggressive prostate cancer. Both had had normal exams not too long before and both had taken the same over-the-internet herbal supplement to enhance muscle strength and sexual performance. Investigators found out that the supplement contained undisclosed ingredients including testosterone, a testicular hormone that can accelerate the clinical course of prostate cancer. In the lab the supplement showed potent growth effects on prostate cancer cells. An adverse event report was filed with the Food and Drug Administration and the product was removed from the market place.
Supplements are not regulated by the FDA. Not surprisingly, we have seen supplements cause harm from time to time. Ephedra and PC-SPES were taken off the market after their use was associated with death. Now an un-named herbal supplement has also been associated with death by prostate cancer.
Until we know how to actively prevent prostate cancer, maybe we can avoid some things that cause it. We already know about cadmium and Agent Orange. If the FDA would regulate supplements, we would also know which of them to avoid.
A final word …
I told a patient about this report about three months after he had prostate cancer surgery. He reacted in horror, confessing juvenile use of human growth hormone and testosterone. Ultimately, he blamed himself for his own prostate cancer. Given his family history of prostate cancer, he had plenty of theoretical reasons for having it and indeed had no basis to blame himself. Still, his reaction raises a question:
Have you taken supplements to strengthen muscles or sexual performance?
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Shariat SF, Lamb DJ, Iyengar RG, Roehrborn CG, Slawin KM. Herbal/Hormonal Dietary Supplement Possibly Associated with Prostate Cancer Progression. Clin Cancer Res 2008 14:607-611.
Kavanaugh CJ, Trumbo PR, Ellwood KC. The US Food and Drug Administration's evidence-based review for qualified health claims: tomatoes, lycopene, and cancer. J Natl Cancer Inst 2007 99:1074-85.
Committee on the Use of Complementary and Alternative Medicine by the American Public. Complementary and Alternative Medicine In the United States. Institute of Medicine of the National Academies. The National Academies Press 2005