Aggressive oral, enteral or parenteral nutrition: prescriptive decisions in children with cancer.

Over the past 18 years, our laboratory has been interested in the pathogenesis of energy imbalance caused by a variety of diseases. Our view is that a clear understanding of the various factors causing negative energy balance, which in turn results in malnutrition, is the most effective way of designing preventive and therapeutic nutritional strategies. Thus, in cancer, one of the common factors is anorexia, due either to the primary tumor or to the effects of cancer therapy. Currently there is little evidence of increased resting energy expenditure in children with cancer, except in cases with very high tumor burden. Conversely, there are suggestions of a failure to down-regulate resting energy expenditure in the presence of reduced food intake in patients with cancer. Damage to the gastrointestinal tract, due to the effects either of the tumor or of tumor therapy, may result in maldigestion and/or malabsorption. Thus, as a result of a combination of reduced intake, reduced absorption and increased needs, the child with cancer may become malnourished. Prevention and treatment are dependent on the type of cancer and the pathogenesis of the negative energy balance. In broad terms, we try as far as possible to use external routes. With the advent of percutaneously placed gastrostomies and gastrojejunal tubes, we use these methods increasingly to provide nutritional support. Only in patients whose gastrointestinal tract cannot be used do we turn to i.v. feeding. In these patients, the placement of a central venous line is required, but great care must be taken to avoid infection. Whatever form of nutritional support is used, whether enteral or parenteral, we measure the body composition and energy expenditure in the patient, so that the nutritional therapy can be tailored to the child's specific needs. Using these approaches, we are having significant success in preventing and reversing malnutrition in children with cancer and those undergoing bone-marrow transplantation.