Resting energy expenditure in lung and colon cancer.

Elevated resting energy expenditure (REE) is a possible mechanism of cancer cachexia. We measured REE by whole-body direct calorimetry in patients with colon and non-small cell lung cancer and compared the results with REE in groups of healthy subjects and in patients with anorexia nervosa, with nonmalignant gastrointestinal (GI) disease, with miscellaneous reasons for weight loss, and with chronic lung disease. The mean REE of the cancer patients was not different from healthy subjects, those with GI disease, miscellaneous causes of cachexia, and chronic lung disease, and there was no significant difference in REE between those cancer patients with weight loss and controls with weight loss, except for the anorexia nervosa patients. The REE of the anorexia nervosa patients (female) was significantly lower than the REE of females with lung cancer. Weight loss correlated with REE in female lung cancer patients. Serial comparison of REE of ten cancer patients who lost 5% to 18% of their body weight during study showed no consistent change in REE. We conclude that patients with colon and non-small cell lung cancer, including those with weight loss, have REE similar to normal controls. Relative hypermetabolism may contribute to cancer cachexia, as may absolute hypermetabolism in some subsets of cancer patients.