ANN ARBOR, Michigan--Prostate cancer patients are increasingly likely to ask their physicians about alternative (or complementary) therapies, and physicians need to know the evidence, or lack of evidence, supporting their use.
"We need to get that information to the physician and to the patient," said Mark A. Moyad, MPH, a clinical cancer researcher and health educator at the University of Michigan Health System. He spoke at a conference designed to do just that--the First International Prostate Cancer Symposium for the Patient, sponsored by the University of Michigan.
At a session on alternative therapies, William Fair, MD, of Memorial Sloan-Kettering, emphasized the importance of reducing fat consumption as a step toward reducing prostate cancer risk or the progression of disease. He recommends that no more than 20% of total daily calories should come from fat, a level supported by experimental lab work.
Mr. Moyad, in his review of the use of various nutritional supplements, highlighted three products that have shown promise in preliminary studies: vitamin E(Drug information on vitamin e), soy products, and green tea. "Vitamin E studies from our laboratory and Dr. Fairs lab show very promising results for prostate cancer patients. Were doing work in animals right now with these supplements," he said in an interview with Oncology News International.
These three supplements, along with reducing dietary fat, he said, "show incredible promise, not just in prostate cancer but in many other cancers and also in possibly reducing heart disease."
All Things in Moderation
When patients are interested in using supplements, Mr. Moyad recommends moderate doses. "My work in supplements suggests clearly that more is not better," he said. For vitamin E, he recommends no more than 200 IU to 400 IU, taken with meals for better absorption. Above 400 IU, he said, there is the possibility that the vitamin will interact with the effects of aspirin(Drug information on aspirin) and blood thinning agents like coumadin and warfarin(Drug information on warfarin).
Another question that comes up with vitamin E is what type to buy "because there are at least 8 or 10 different varieties available," he said. Vitamin E is a general name for a series of different compounds, he pointed out.
"Synthetic vitamin E has been used mainly in studies, but in our lab, were using natural vitamin E, and were finding results as good as those seen with the synthetic product," he said. "So I think, right now, until we know which type is best, patients can use any type."
Mr. Moyad said that green tea, which looks very promising as a cancer preventive, is now often available in grocery stores as well as health food stores, either as a tea or as a supplemental capsule. "I suggest the decaffeinated variety," he said. Although green tea contains less caffeine(Drug information on caffeine) than coffee, it does contain enough to possibly interfere with sleep.
He also advises patients to first try the natural product rather than supplements. Green tea leaves contain at least four or five compounds, called polyphenols, that may have an anticancer effect. "You get all those compounds when you drink the product whereas supplements generally contain significant quantities of only one or two of the compounds," he said.
Mr. Moyad suggested caution in the use of other nutritional supplements for which there is less information available. He mentioned two supplements, recently touted as being very promising as anticancer compounds, that may actually have the opposite effect, according to early results.
One example is lycopene, an antioxidant found in tomatoes, that, when studied in Dr. Fairs lab at Sloan-Kettering, was shown to promote tumor growth rather than decrease it, as other work has suggested.
Results With Co-enzyme Q
Mr. Moyads group has recently looked at a supplement called co-enzyme Q, which has been gaining popularity among patients as an anticancer therapy. They found that it did not decrease prostate cancer cell growth but, rather, increased it in a dose-dependent manner. "The more we added, the more the tumor cells grew," he said.
Such conflicting studies confirm the importance of making sure that physicians have the facts about supplements--both positive and negative evidence.
Two alternative techniques--acupuncture and meditation--may play a supplemental role in prostate cancer treatment, not in reducing tumor growth but "by possibly doing other things that can be helpful, such as lowering blood pressure and reducing stress," Mr. Moyad said.
Meditation is being used in cancer support groups across the country to help reduce the stress of living with cancer and its treatment. Although there are as yet no studies of acupuncture in prostate cancer, he noted that the NIH recently gave its seal of approval for acupuncture as an adjunctive therapy in treating chemotherapy-related nausea and cancer pain. "Prostate cancer patients often get chemotherapy and often have significant pain," Mr. Moyad said, "so it definitely looks like acupuncture is going to have a use in the future with prostate cancer as a complementary therapy."