Measurements of resting energy expenditure and body composition before and after treatment of small cell lung cancer.
Jebb SA., Osborne RJ., Dixon AK., Bleehen NM., Elia M.
BACKGROUND: Many patients with small cell lung cancer are reported to lose weight, but the mechanism of this effect is unclear. PATIENTS AND METHODS: Measurements of resting energy expenditure (REE), using indirect calorimetry and body composition (fat, fat-free mass and organ mass), using dual energy X-ray absorptiometry (DXA) and abdominal CT scans were measured in 38 patients with newly-diagnosed small cell lung cancer. Twenty-eight patients were restudied at the end of treatment. RESULTS: In those who responded to treatment there was no change in body weight, but a decrease in REE of 15.7 +/- 11.7 kJ/kg fat free mass/day, whilst in the non-responders body weight decreased 4.33 +/- 5.4 kg, but REE was unchanged. CONCLUSIONS: This study provides evidence for tumour-induced hypermetabolism which is independent of changes in gross body composition, although the absolute increase is small, approximately 0.8 MJ/day. However since body weight was maintained in those patients who responded to treatment either total energy expenditure was decreased, implying decreases in physical activity, or energy intake was increased.