Neuroendocrine Tumors: A Comprehensive Review on Nutritional Approaches

Simple Summary Neuroendocrine neoplasms and their main subtype neuroendocrine tumors have an increasing incidence worldwide, associated with a high survival and prevalence rate. Both the tumor itself and systemic therapy can have an impact on patients' nutrition. Conversely, preliminary data suggest that malnutrition has a negative impact on the development and prognosis of neuroendocrine tumors, as does obesity. The aim of this review is to condense the latest evidence on the role of the most widely used dietary patterns, the Mediterranean diet, the ketogenic diet and intermittent fasting, in the context of neuroendocrine tumors. Nutritional plans are an integral part of the multidisciplinary treatment team of patients with neuroendocrine tumors because they improve the patient's quality of life. The nutritional approach must be tailored, based on nutritional needs and nutritionally manageable signs and/or symptoms related to drug treatment. Neuroendocrine neoplasms are a heterogeneous group of neoplasms with increasing incidence, high prevalence, and survival worldwide. About 90% of cases are well differentiated forms, the so-called neuroendocrine tumors (NETs), with slow proliferation rates and prolonged survival but frequent development of liver metastases and endocrine syndromes. Both the tumor itself and systemic therapy may have an impact on patient nutrition. Malnutrition has a negative impact on outcome in patients with NETs, as well as obesity. In addition, obesity and metabolic syndrome have been shown to be risk factors for both the development and prognosis of NET. Therefore, dietary assessment based on body composition and lifestyle modifications should be an integral part of the treatment of NET patients. Nutrition plans, properly formulated by a dietician, are an integral part of the multidisciplinary treatment team for patients with NETs because they allow an improvement in quality of life, providing a tailored approach based on nutritional needs and nutritional manageable signs and/or symptoms related to pharmacological treatment. The aim of this review is to condense the latest evidence on the role of the most used dietary models, the Mediterranean diet, the ketogenic diet, and intermittent fasting, in the context of NETs, while considering the clinical and molecular mechanisms by which these dietary models act.