Nutrition treatment does not improve the efficacy of oncological treatment

A beneficial effect of nutrition treatment on multiple aspects of oncological therapy is chiefly demonstrated by pre­venting and in treating the wasting syndrome and cancer cachexia accompanying the cancer disease. The presence of the wasting syndrome prior to commencing treatment is associated with shorter time for developing complications along with a shorter overall survival (OS), worse response to oncological treatment, deteriorating quality of life, poorer general status; moreover, cachexia strongly affects treatment tolerance. Clinical nutrition is one of the most significant pillars supporting oncological treatment, nonetheless, one has to be mindful of certain cases where nutritional inte­rvention, especially parenteral nutrition, does not bring benefits, and may even be harmful to the patient. Such cases include: PN (parenteral nutrition) for patients with normal body mass and a correctly functioning gastrointestinal tract; PN due to hypoalbuminemia, in patients where feeding via the gastrointestinal tract is possible (orally or enterally); lack of refeeding syndrome prevention for cachectic patients starting PN or EN; use of feeding mixtures containing only soya oil as the sole fatty nutrient; incomplete nutrition (macronutrients or micronutrients only); inclusion of PN in patients in the terminal phase of cancer undergoing persistent nutrition therapy.