In spite of major advances in cancer treatment over the past decades, unproven or ineffective methods of treatment continue to be offered to the public by unqualified or unscrupulous practitioners. These methods fall into five categories: devices, tests, drugs, diets, and psychological methods, as well as combinations of these. The emotional, physical, and financial burdens of cancer treatment make cancer patients and their families especially vulnerable to the pitch of these operators. Participation in worthless treatments can lead to loss of life or prolongation of illness which might otherwise have been avoided through orthodox cancer treatment. Ineffective treatments can generally be recognized by application of some simple guidelines. Lack of faith in the medical care system is an important motivation in the choice of alternative therapies. Health practitioners have an obligation to be sensitive to patients' needs, and to provide emotional as well as medical support, to communicate openly with patients and families, and to nurture the trust that will prevent abandonment of traditional medical care in favor of quackery.mag