Complementary and alternative medicine (CAM) use by patients enrolled in phase I clinical trials

Abstract

8053 Background: CAM usage among cancer patients is common, but usage in patients enrolled in phase I trials is unknown. There are potential pharmacologic interactions between CAM agents and experimental cancer therapies. This study describes the prevalence, clinical characteristics, and patterns of CAM use among patients enrolled in phase I trials. Methods: Investigator-designed questionnaires were administered to 108 patients with advanced malignancies enrolled in phase I chemotherapy trials at Mayo Clinic. CAM was classified as pharmacologic and non-pharmacologic. Results: 88.2% of respondents (90/102) used at least one CAM modality of whom 93.3% (84/90) used pharmacologic and 53.3% (48/90) used non-pharmacologic form of CAM. 46.7% (42/90) combined both approaches. 91.1% of CAM users had received prior standard chemotherapy. Overall, CAM use was higher among females than males (53.5% vs. 40.4%). Vitamin and mineral supplements (vitamin E 48.8%; vitamin C 38.1%) constituted 89.3% of pharmacologic CAM use. 71.4% of patients took non-vitamin, non-mineral pharmacologic CAM preparations of which green tea (29.8%), echinacea (13.1%) and essiac (9.5%) were the most popular. Spirituality (prayer and faith) was the most commonly practiced non-pharmacologic form of CAM, accounting for 52.1%. Chiropractors, the most frequently visited non-traditional medical practitioners, were consulted by only 10% of CAM users. Conclusion: CAM use is widespread among phase I patients. This increases the potential for anti-cancer drug interactions with such CAM agents as green tea and echinacea which are known to affect hepatic drug metabolism. Essiac contains cytotoxic anthraquinones and other substances that interact with hormone receptors ( e.g. estrogen). Investigators should ascertain the CAM therapies utilized by patients as interactions between CAM agents and experimental agents can potentially lead to increased toxicity or alter efficacy of experimental drug therapy. No significant financial relationships to disclose.