Energy balance in nonsmall cell lung carcinoma patients before and after surgical resection of their tumors.

BACKGROUND: The purpose of this study was to investigate whether surgical removal of a tumor influences energy balance, body weight, and body composition in lung carcinoma patients. METHODS: In 53 nonsmall cell lung carcinoma (NSCLC) patients, resting energy expenditure (REE, measured by ventilated hood), energy intake (EI, determined by diet history), body weight, and body composition (fat free mass [FFM], measured by bioelectrical impedance analysis) were all determined before tumor resection. In 39 of 53 patients, REE, EI, body weight, and body composition were also measured 3, 6, and 12 months after tumor resection. RESULTS: Thirty-six of 53 patients (68%) were found to be hypermetabolic. Fourteen patients were excluded from the repeated measurements. Patients with curative tumor resection (n = 30) showed an increase in body weight over a 1-year period, in contrast to patients with tumor recurrence (n = 9), who lost weight (+3.5 vs. -3.6 kg, P < 0.005). The weight gain was caused predominantly by an increase in fat mass (FM), while the weight loss was caused for more than half by a decrease in FFM. Body weight was increased in hypermetabolic patients (n = 20) as well as patients with normal metabolism (n = 10) 1 year after successful removal of their tumors. However, although EI/REE was significantly increased in hypermetabolic patients (from 106% to 140%, P < 0.05), it was not changed in patients with normal metabolism. CONCLUSIONS: Hypermetabolic NSCLC patients undergoing curative resection show an improvement in energy balance caused by both a decrease in REE and an increase in EI. This positive energy balance results in weight gain, which is caused predominantly by an increase in FM.