Nutritional support of the patient with esophageal cancer.

M ALNUTRITION is a common finding in patients with esophageal cancer,’ and the resultant cachexia is implicated as a cause of death in approximately 18%’ The etiology of cancer cachexia, a syndrome of emaciation, debilitation, and malnutrition3 is unknown.4.5 Multiple factors contribute to this syndrome, but in most circumstances weight loss, debilitation, and weakness progress, and hypophagia clearly becomes the dominant factor.’ Possible mechanisms of cancer cachexia include: (1) anorexia secondary to hypothalamic dysfunction,’ taste and smell abnormalities,*s9 learned food aversions,” and complications of antineoplastic therapy”m~‘3; (2) increased energy expenditure’“‘6; and (3) tumor-host competition for substrates.“-*’ Although postulated, there is no direct evidence that hypothalamic dysfunction contributes to the anorexia of cancer. In fact, animal studies are interpreted to show that the hypothalamus functions normally in cancer.’ In man, the hypothalamus probably plays a minor role, if any, as the cause of anorexia in cancer. Abnormalities of taste have been documented in heterogeneous groups of cancer patients compared to controls.‘.“*’ DeWys and Walkers demonstrated that the presence of a taste abnormality correlated with the extent of tumor burden.” In patients with esophageal cancer, Kamath et al23 were unable to detect a taste abnormality in 12 untreated patients compared to 14 controls matched for age, smoking habits, and alcohol consumption (Table 1). There was no significant difference between esophageal-cancer patients and matched controls in ability to detect or recognize the four basic tastes. Anorexia has been attributed to learned food aversions by some investigators. Bernstein has suggested that learned food aversions can be secondary to the association of a diet with aversive physiological effects of the tumor itself, or secondary to the association of a diet with the toxicities of antineoplastic therapy.‘0,24 Although of great interest, data to support this concept as a universal mechanism for anorexia in esophageal cancer and other neoplasms are sparse.