The role of the nutrition in malnourished cancer patients: Revisiting an old dilemma

Abstract

Background & aimsGLIM definition of malnutrition is recognised all over the world and, when is referring to cancer, it specifies that weight or muscle loss are associated with an inflammatory status. However, the real-world practice shows that GLIM definition cannot encompass all the wide and heterogenous clinical presentations of cancer patients with malnutrition, which involves many other drivers beyond inflammation. Moreover, placing an excessive emphasis on the inflammation can overshadow, in the clinical practice, the role of the nutritional support in malnourished cancer patients. The aim of this paper is not to criticize the rationale of the GLIM definition of cancer cachexia, but to show the complexity and heterogeneity of malnutrition of cancer patients and reasons why nutritional support should deserve such a better consideration among the oncologists. MethodsLiterature pertinent to pathophysiology of malnutrition of cancer patients is scrutinised and reasons for the frequent underuse of nutritional support are critically analysed. ResultsThe appraisal of the literature shows that there are various pathophysiological patterns of malnutrition among cancer patients and inflammatory markers are not universally present in weight-losing cancer patients. Inflammation alone does not account for weight loss in all cancer patients and factors other than inflammation can drive hypophagia and weight loss, and hypophagia appears to be a primary catalyst for weight loss. Furthermore, malnutrition may be the consequence of the presence of several Nutrition Impact Symptoms or of the oncologic therapy.The nutritional support may fail to show benefits in malnourished cancer patients because the golden standard to validate a therapy relies on RCT, but it is ethically impossible to have an unfed control group of malnourished patients. Furthermore, nutritional interventions often fell short of the optimal standards, adherence to treatment plans was often poor, nutritional support was mainly reserved for very advanced patients and the primary endpoints of the studies on nutritional support were sometimes unrealistic. ConclusionThere is a gap between the suggestion of the guidelines which advocate the use of nutritional support to improve the compliance of patients facing intensive oncologic treatments or to prevent an early demise when patients enter a chronic phase of slow nutritional deterioration, and the poor use of nutrition in the real-world practice. This requires a higher level of awareness of the oncologists concerning the reasons for the lacking evidence of efficacy of the nutritional support and an understanding of its potential contribute to improve the outcome of the patients. Finally, this paper calls for a change of the oncologist’s approach to the cancer patient, from only focusing on the cure of the tumour to taking care of the patient as a whole.