Evaluating complementary and alternative therapies for cancer patients.

"Complementary and alternative" therapies are actually a vast collection of disparate, unrelated regimens and products, ranging from adjunctive modalities that effectively enhance quality of life and promising antitumor herbal remedies now under investigation, to bogus therapies that claim to cure cancer and that harm not only directly, but also indirectly by encouraging patients to avoid or postpone effective cancer care. Complementary therapies such as music and massage, herbal teas to aid digestion and relieve nausea, yoga, tai chi, meditation, and the many other well-documented techniques that relieve stress and enhance well-being should be made available to patients to augment and ease the experience of cancer treatment and recovery. Many time-tested herbal and diet-based remedies are now being studied for their abilities to induce or extend remission without toxicity. At the same time, lack of government regulatory authority leaves consumers at the mercy of those who promote unproved remedies, scores of which the grocery store and pharmacy shelves. Many of these over-the-counter products contain harmful ingredients. Herb-drug interactions, only some of which are documented, occur with frequency and are sufficiently problematic to require that patients stop taking herbal remedies prior to surgery (to prevent interactions with anesthetics and anticoagulant effects); before radiation (due to potential for increased photosensitivity); and during courses of chemotherapy (to prevent product-drug interactions). Moreover, both good information and misinformation that appear in printed materials and on the Internet appeal to better educated consumers, who are, in fact, the most likely to try complementary and alternative methods.