Is the intravenous supplementation of amino acid to cancer patients adequate? A critical appraisal of literature

Background Ea aims: International guidelines are quite vague regarding the optimal doses of amino acid to administer to cancer patients and standard practice appears not to be supported by specific investigations. The purpose of this study is to determine from the literature whether there are some correlates among amino acid infusions and nutritional-metabolic or clinical outcomes. Methods: Through the help of PubMed (www.ncbi.nlm.nih.gov) and the use of a personal database we analysed papers reporting details of infused amino acid and metabolic-nutritional or clinical effects. Results: Five short-term metabolic studies using isotopes showed that infusion of about 2 g amino acid/kg/day (including high doses of branched chain amino acid) positively affects protein metabolism of severely malnourished cancer patients. In eight studies in less malnourished patients receiving longer periods of parenteral nutrition, to allow the administration of oncologic therapy or to compensate for a decline in oral alimentation, the intravenous addition of 1.5 g amino acid/kg/day to the oral diet achieved positive results. These findings are concordant with recent metabolic results achieved in cancer patients receiving amino acid orally. Conclusion: We think that a higher quantity of parenteral amino acids than that usually administered might be useful to cancer patients and further studies on this issue are warranted. (C) 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.