Efficacy of enteral and parenteral nutrition in cancer patients.

Before attempting to analyze the potential efficacy of the two different routes of administering nutrients to cancer patients, enteral nutrition (EN) versus total parenteral nutrition (TPN), it should be appreciated that patients who are usually fed via a vein are not the same as those who receive EN. If fact, nowadays, the option for TPN only emerges if a patient is not suitable for EN because his/her gut is not working. Consequently the different effects of EN and TPN cannot be attributed only to the administration route of nutrients, but also to the different basic conditions of these 2 groups of patients. There are, however, some exceptions: at the beginning of the era of artificial nutrition, TPN was more developed than EN probably because the impetus of this new approach relied on an urgent need to solve the problems of patients with intestinal failure. In fact, initially TPN was developed in surgical departments to meet the nutritional requirements of patients with short-bowel syndrome or abdominal catastrophes. This translated into the use of TPN also in patients with a working gut, and finally rendered a comparison between TPN and EN not only possible, but even scientifically rational and ethically acceptable. At this point we were roughly in the 1980s. Another field where TPN and EN are frequently compared is the perioperative setting. Nutritional support in the perioperative period is not nutrition in the traditional meaning of the word: it is the attempt to control the metabolic reaction to surgical trauma and to potentiate the defenses of the patient through the administration of nutrients. The indication for nutritional support in this patient population was questioned for a long time and the simple provision of a saline solution for a few days was usually accepted in many institutions. Consequently in the literature there are studies comparing not only different nutritional regimens and Lochs H, Thomas DR (eds): Home Care Enteral Feeding. Nestlé Nutrition Workshop Series Clinical & Performance Program, vol 10, pp 127–142, Nestec Ltd., Vevey/S. Karger AG, Basel, © 2005.