Why do some cancer patients receiving chemotherapy choose to take complementary and alternative medicines and what are the risks?

Complementary and alternative medicine (CAM) cover a broad and diverse group of treatments and products that do not tend to be widely used by conventional healthcare professions. CAM that is systemically absorbed is the most likely to interfere with concurrent chemotherapy and potentially cause harm to cancer patients. Patients receiving chemotherapy may be consuming CAM to treat cancer, to lessen chemotherapy side effects, for symptom management, or to treat conditions unrelated to their cancer. A small proportion of cancer patients decide to use CAM alone to treat cancer and delay conventional treatment. Cancer patients may be influenced in their CAM decision-making by others: practitioners, family, friends, spouse and even casual acquaintances met in waiting rooms and support groups. This influence may range from encouraging and supporting the patient's decision through to making the decisions for the patient. When tested in rigorous clinical trials, no CAM cancer treatments alone have shown benefit beyond placebo. With the exception of ginger to treat chemotherapy-induced nausea, there is no compelling evidence overriding risk to take complementary medicines for supportive care during chemotherapy treatment. There is, however, established evidence to use mind-body complementary therapies for supportive care during chemotherapy treatment.