The numbers are a "wake-up call" to clinicians who may think elderly men (those most likely to be diagnosed with prostate cancer) are less likely to use complementary medicine, says Professor Heather Boon of U of T's Leslie Dan Faculty of Pharmacy, lead author of the study published in the November issue of the journal Urology. "Usually we see younger people and women as the most common users but clearly it's a phenomenon that's happening in all ages and all genders. Clinicians need to be aware of this and discuss it with their patients."
The study, based on a random sample survey of 696 Ontario men diagnosed with prostate cancer, found that 29.8 per cent of respondents used complementary medicine. Some 26.5 per cent of those used natural health products, most commonly vitamin E, saw palmetto and selenium. This finding raises concerns about the potential for adverse interactions, says Boon. For example, taking a product such as vitamin E – an antioxidant – might actually diminish the effectiveness of some conventional therapies because antioxidants may interfere with how some radiation therapy and chemotherapy work.
"For some of these products, it's not clear whether taking them at the same time as conventional therapy is a good idea or not," says Boon. "In most cases we don't have definitive evidence about whether they're bad or good." She noted that while saw palmetto, for example, may be useful in the management of benign enlarged prostate, it has not been proven effective against prostate cancer.
The study was funded by the Canadian Institutes of Health Research and included co-researchers from U of T, the University of Western Ontario, Toronto-Sunnybrook Regional Cancer Centre, University Health Network and the London Regional Cancer Centre.
CONTACT: Professor Heather Boon, Leslie Dan Faculty of Pharmacy, 416-946-5859, heather.boon@utoronto.ca or Jessica Whiteside, U of T public affairs, 416-978-5948, jessica.whiteside@utoronto.ca
Journal
Urology