Some practical and theoretic concepts in the nutritional assessment of the cancer patient.

Two patterns of response, that due to starvation or semistarvation and that due the stress, determine whether protein-calorie malnutrition of the adult marasmus variety or hypoalbuminemic malnutrition will occur in any particular nonmalignant disease. The latter condition can have two major components, the neuroendocrine response to injury, which is in large measure mediated by hormones of the hypothalamus and adrenal gland, and the panoply of responses to interleukin-1 production and release by macrophages and monocytes upon activation, usually by phagocytosis. In some cancer patients with weight loss there are many similarities to an interleukin-1 response including increases in resting energy expenditure, whole-body protein flux and synthesis and glucose flux and recycling, hypoalbuminemia and increased albumin catabolic rates, and an adaptive low T3 state that suggest a similar injury/infection response. Separation of cancer patients with malnutrition into those with an injury/infection response and those with simple starvation may explain the heterogeneous response to nutritional support among malnourished cancer patients and suggest new feeding regimens that may uniquely benefit the stress form of cancer malnutrition.