High Prevalence of Complementary and Alternative Medicine Use Among Cancer Patients: Implications for Research and Clinical Care

In this issue, Hyodo et al report that herbs and other dietary supplements are used by substantial numbers of cancer patients in Japan— 44.6% of 3,100 patients, as opposed to 25.5% of 361 noncancer (benign tumor) patients surveyed. These data are consistent with results from numerous prior surveys on complementary and alternative medicine (CAM) use in oncology. A 1998 systematic review examined 26 surveys of cancer patients from 13 countries and reported an average prevalence of 31%, with rates ranging up to 64%. Subsequent studies report even higher prevalence, depending on the definition of CAM used. Reports of prevalence often are exaggerated because surveyors include many aspects of life, such as spirituality, attention to diet, and routine self-care, that from our perspective are not complementary therapies. Nonetheless, use of complementary therapies by cancer patients is substantial. Virtually all studies conducted internationally, such as that reported here, indicate that people who seek complementary therapies are better educated, of higher socioeconomic status, and more likely to be female and younger than those who do not. Data from Hyodo et al show that herbs and supplements, which are directed primarily at cancer control, are used much more commonly in Japan than are the symptom management complementary therapies more typically sought in North America. This difference is also of interest because, despite some promising agents, most herbs and other supplements as currently available are of questionable value, whereas substantial evidence from randomized trials supports the use of complementary therapies for symptom control in patients with cancer, including acupuncture, massage, music therapy, and relaxation techniques. In the survey by Hyodo et al, more than 96% of patients used Chinese herbs, mushrooms, shark cartilage, vitamins, and so on (Table 3 of Hyodo et al ). Not mentioned in this article, however, are Japan’s Kampo products, which are based on traditional Chinese herbal formulas. Kampo botanicals are produced at a pharmaceutical grade, available in pharmacies by prescription, and commonly prescribed by physicians in Japan. This survey excluded Kampo products, explicitly defining CAM as remedies used without the approval of relevant government authorities and not covered by health insurance. Many Kampo products, conversely, are approved by the Japanese government and are covered by health insurance. Essentially, they are high-quality, standardized, government-regulated versions of herbal medicines, which in the West are termed dietary supplements. In North America, however, dietary supplements do not meet the same standards as do the governmentregulated Kampo products in Japan. Ours are poorly standardized, often contaminated, usually not evidence based, and unregulated, and may be dangerous in the oncology setting. Herbs and other supplements are not required to meet standards of safety, efficacy, and consistency, and their use has important implications for clinical care. The continuing availability of such products in the United States results in large part from the 1994 Dietary Supplement and Health Education Act, which created a protective new category for the approximately 20,000 vitamins, minerals, herbs, and other agents sold as supplements before October 1994. Spurred by supplement industry lobbying, the act protects supplements from government scrutiny and mandates that the US Food and Drug Administration prove harm before distribution of a product can be regulated. JOURNAL OF CLINICAL ONCOLOGY E D I T O R I A L VOLUME 23 NUMBER 12 APRIL 2