Nutritional support of the cancer patient: issues and dilemmas

Malnutrition in cancer patients results from multifactorial events and is a ssociated with an alteration of quality of life and a reduced survival. A s imple nutritional assessment program and early counselling by a dietitian a re essential to guide nutritional support and to alert the physician to the need for enteral (EN) or parenteral nutrition (PN). A daily intake of 20-3 5 kcal/kg, with a balanced contribution of glucose and lipids, and of 0.2-0 .35 g nitrogen/kg is recommended both for EN and PN, with an adequate provi sion of electrolytes, trace elements and vitamins. EN, always preferable fo r patients with an intact digestive tract, and PN are both safe and effecti ve methods of administering nutrients. The general results in clinical prac tice suggest no tumor growth during nutritional support. The indiscriminate use of conventional EN and PN is not indicated in well-nourished cancer pa tients or in patients with mild malnutrition. EN or PN is not clinically ef ficacious for patients treated with chemotherapy or radiotherapy, unless th ere are prolonged periods of GI toxicity, as in the case of bone marrow tra nsplant patients. Severely malnourished cancer patients undergoing major vi sceral surgery may benefit from perioperative nutritional support, preferab ly via enteral access. Nutritional support in palliative care should be bas ed on the potential risks and benefits of EN and PN, and on the patient's a nd family's wishes. Research is currently directed toward the impact of nut ritional pharmacology on the clinical outcome of cancer patients. Glutamine -supplemented PN is probably beneficial, in bone marrow transplant patients . Immune diets are likely to reduce the rate of infectious complications an d the length of hospital stay after GI surgery. Further studies are needed to determine the efficacy of such novel approaches in specific populations of cancer patients, and should also address the question of the overall cos t-benefit ratio of nutritional pharmacology, and the effect of nutritional support on length and quality of life. (C) 2000 Published by Elsevier Scien ce Ireland Ltd. All rights reserved.