Malnutrition in oncology: etiology, pathogenesis, and principles of correction

Cancer is currently one of the leading causes of death. Mortality in this group of patients is due to both underlying disease course and therapy complications. The development of cachexia is one of the most important factors that affect both the quality of life of a patient with cancer and the treatment effectiveness. Presently, ideas about the pathogenesis of malnutrition in patients with cancer and its diagnostic methods are fairly clear. However, a particular patient needs to understand which processes are leading to the development of anorexia-cachexia syndrome. Concepts, such as anorexia, cachexia, and sarcopenia, reflect various possible variants of the course or stage of developing metabolic disorders. Their timely detection determines the duration and process intensity and assesses the prognosis of the disease course, as well as develops a patient-oriented nutritional support program. Understanding the pathogenesis of its development allows for the correction of emerging disorders throughout the patient treatment period. Nutritional therapy is a key method that can influence the severity of cachexia. Undoubtingly, the progression of malnutrition is due to the multimodal effect of the tumor on the patients metabolism and can significantly affect the effectiveness of antitumor therapy. Therefore, basic principles of diagnosis and treatment are formulated, including early diagnosis, individual nutritional need calculation (proteins, energy), and the use of pharmaconutrients that can influence the severity of catabolic processes. According to the patient-orientation concept, an oncologist should be involved in the formation of a nutritional therapy program, which allows a simultaneous selection of the most optimal scheme of specialized nutrition based on the patients condition, type and stage of neoplasm, nutrient introduction restrictions, taste preferences, and timely qualitative and quantitative nutrient composition adjustment against the background of the changing patient condition and needs. The maximum effectiveness of nutritional support in patients with cancer can be achieved only with a multimodal approach of correcting all pathological processes that lead to malnutrition occurrence and progression.