Prevention with Guest Blogger Arnon Krongrad, M.D.

I have invited Dr. Arnon Krongrad, M.D. to submit an occasional post. He is a pioneer of the Laparoscopic Radical Prostatectomy and currently practices at the Krongrad Institute in Aventura Florida.

In addition, Dr. Krongrad’s closing remark, “For now, the key to effective management remains detection and treatment.” has a special resonance for me in light of yesterdays post about the potential of the American Cancer Society deciding to turn away from their aggressive advocacy on screening.

Joel T. Nowak, MA, MSW

I received an email: “Stop scaring everyone. Just tell us how to prevent prostate cancer.” The email was in response to an article I had written about prostate cancer prevention. My argument was that we do not know how to prevent prostate cancer, which the reader did not want to accept. Let us review.

To prevent illness requires that we first identify factors that correlate with it. Some such factors are not useful because they cannot be modified. For example, prostate cancer incidence goes up with age, black race, and family history. None can be modified and none can be a basis for a strategy to prostate cancer prevention (you cannot modify when you were born and to whom). We limit our efforts at prevention to things that go with prostate cancer that can be modified.

One type of prevention strategy is to do things that decrease risk. This type of strategy is common. For example, we add fluoride to our drinking water so as to prevent dental cavities. With prostate cancer, two drugs are currently under investigation as preventives: finasteride and dutasteride. Neither has been proved to be a preventive and trials are ongoing. There are also studies of dietary supplements of selenium. When we published the original selenium prevention study in 1996, they stirred considerable interest because of a huge apparent preventive effect. Still the study had limits, as reviewed in the article that prompted the email. More to the point, a 2007 study from the National Cancer Institute showed an almost 6-fold increase in fatal prostate cancer in men who take selenium in addition to multivitamins. At best, the data on selenium are intriguing but contradictory. At worst, they suggest that selenium actually accelerates prostate cancer.

A second type of strategy is to avoid things that increase risk. This type of strategy is in common use, as for example when we avoid cigarette smoking to prevent lung cancer. Such would be the case with prostate cancer in regards to cadmium and Agent Orange, both of which are associated with prostate cancer risk. However, few men are exposed to these two agents such that it is of little public health value to warn against them.

A recent report suggests that there may be something else to be avoided: over-the-counter supplements. In an unprecedented study of two men with advanced prostate cancer it was shown that supplements, which are not well regulated, may contain unlisted ingredients. In this particular case, the supplements included testosterone. In the laboratory, they were shown to potently promote the growth of prostate cancer cells. In this case, the FDA reportedly took the supplement off the market. Given that supplements are not regulated, we cannot be sure the danger is not still with us with other products. Until we can be sure, we cannot further develop prevention strategies around avoidance of potentially dangerous supplements.

The bottom line is that despite intense interest we are not yet at a point of rational prostate cancer prevention strategies. For now, the key to effective management remains detection and treatment.

Guest blogger Arnon Krongrad, MD is author of “Behind the Mask: Reflections of a Prostate Cancer Surgeon,” a series published by the Miami Herald. Essays are archived at http://www.laprp.com/editorials.php