Physiological and psychological mechanisms of cancer anorexia

Recent research addressing possible causes of the decline in spontaneous food intake which accompanies tumor growth and antitumor therapies is reviewed. Investigations of whether disruptions in brain mechanisms involved in feeding are responsible for cancer anorexia are briefly summarized. Studies evaluating the contributions of learned food aversions to the anorexia induced by tumors and antitumor therapy are discussed in some detail. Evidence is presented, from both the clinic and the laboratory, that learned food aversions occur as a result of the association of foods with the discomfort induced by chemotherapy and/or tumor growth. The possible role these aversions play in the etiology of cancer anorexia is discussed, and studies aimed at developing methods for preventing them are described.