Resting metabolic rate of esophageal carcinoma patients: a model for energy expenditure measurement in a homogenous cancer population.

In cancer patients controversy exists as to the nature of changes in resting metabolic rate (RMR) and their contribution to cachexia. This study describes the fasting indirect calorimetry, and nutritional measurements made on a homogeneous group of Black patients with carcinoma of the esophagus. It compares them with a reference group. All cancer patients had localized disease and were markedly malnourished. They were on average 20 to 25% lighter than reference subjects. In the cancer patients, the triceps skinfold thickness (TSF) in mm and the hand grip strength in kg/m2, mean and SD, were, respectively, 7.3 +/- 2.8 and 28 +/- 6 for men and 12 +/- 5 and 22 +/- 3.5 for women, and were significantly lower than those of the reference subjects. Fat-free mass was calculated from the TSF measurements. In men with cancer RMR (6.06 MJ/day +/- 0.56) was significantly lower than the reference subjects values (7.07 MJ/day +/- 0.64) p = 0.002. In women with cancer RMR was on average 2 MJ/day less than in controls but this difference failed to reach significance. However, when expressed per kg fat free mass, or per kg body weight this difference is no longer apparent the RMR being 0.14 MJ/kg/fat free mass in both groups. Our interpretation is that there is no direct effect of the tumour on RMR and that energy expenditure changes are secondary to body composition changes.