Evidence-based complementary and alternative medicine for cancer prevention

Cancer prevention with complementary and alternative medicine (CAM), especially based upon biologically-based practices, is a major concern among physicians, health care providers, and general population. Biologically-based practices include diet-based therapies, botanicals and herbs, vitamins and minerals, animal-derived extracts, and amino acids. We searched databases since the late 1990s and reviewed what have been done in the area of cancer prevention with specific CAM therapies to provide the most recent and updated materials and to be able to serve as a reference for physicians. Scottish Intercollegiate Guidelines Network (SIGN) and National Institute for Clinical Excellence (NICE) methodologies were adopted to classify the study design, study quality assessment, and determination of the evidence level. Some have more or less protective effects but there are conflicting evidences regarding the effectiveness of certain CAM therapies for the prevention of cancer, and most of them are epidemiologic studies, whereas clinical trials are relatively rare in the context of evidence-based medicine (EBM). More researches are mandatory to assess the effectiveness for the prevention of cancer by specific CAM therapies that allow the clinicians and health care providers to give EBM based advice to the patients and inspire them to study CAM therapies for cancer prevention.