Etiology of anorexia in cancer.

Although the causes of cancer anorexia remain poorly understood, it now seems evident that the symptoms of appetite and weight loss which occur in cancer patients are multiply-determined. Thus, the actual causes of specific clinical problems will depend on the type of disease and treatment involved. This report examines research aimed at understanding the mechanisms responsible for cancer anorexia. Particular emphasis is placed on studies examining the contribution of learned food aversions to the anorexia induced by tumors and antitumor therapy. Evidence from the clinic and the laboratory indicates that learned food aversions occur as a result of the association of foods with symptoms induced by chemotherapy and/or tumor growth. The role these aversions play in the etiology of cancer anorexia is discussed and studies aimed at developing methods for preventing them are described.