[Characteristics of nutrient utilization in cancer patients]

The anabolic utilization of nutrients can be modified or impaired due to the influence of a malignant tumor in animals and in humans. Tumor-associated malnutrition as well as the side-effects of several antineoplastic regimens may induce mucosal atrophy, and by this the intestinal absorption of nutrients becomes impaired. Intensified nutrition therapy by oral, enteral or parenteral access is able to maintain or improve the nutritional status of tumor patients. The daily need of substrates can be enhanced as a consequence of the tumor-induced stimulation of proteolysis, gluconeogenesis, hepatic protein synthesis, as well as of an impaired protein metabolism. In the last years, a lot of antimetabolites have been tested for antineoplastic treatment. So far, there is no drug of this kind known, which reduces tumor growth without harm for the tumor-bearing host.