Nutritional status and gastroenteropancreatic neuroendocrine neoplasms: lights and shadows with a clinical guide from the NIKE Group

Neuroendocrine neoplasms (NENs) originating in the gastroenteropancreatic (GEP) tract are rare tumors often associated with significant metabolic disturbances and nutritional challenges. This review explores the intricate relationship between nutritional status and the development, progression, and prognosis of GEP-NENs. Through an extensive literature search encompassing studies up to April 2024, we examined various factors, including obesity, malnutrition, metabolic syndrome and type 2 diabetes mellitus, and their roles in the development and progression of GEP-NENs. The review highlights the dual role of obesity, both as a risk factor and a potential prognostic indicator, drawing attention to the 'obesity paradox' observed in cancer research. Additionally, we discuss the impact of malnutrition on patient outcomes and emphasize the need for comprehensive nutritional assessments beyond BMI. This analysis highlights the importance of incorporating nutritional interventions into preventive and therapeutic strategies for GEP-NEN patients. Future research should further clarify these associations and develop personalized nutritional management protocols to improve patient prognosis and quality of life. Acronyms adopted in the text and tables: AOR: adjusted odd ratio, BIA: Bioelectrical Impedance Analysis, BMI: Body Mass Index, CI: confidence interval, CLARINET: Controlled Study of Lanreotide Antiproliferative Response in Neuroendocrine Tumor, FLI: fatty liver index, GEP: gastroenteropancreatic, GLIM: global leadership into malnutrition, HR: hazard ratio, MS: metabolic syndrome, MUST: malabsorption universal screening tool, NEC: neuroendocrine carcinoma, NENs: Neuroendocrine neoplasms, NETs: Neuroendocrine tumors, NRS: Nutritional Risk Screening, OR: odd ratio, OS: overall survival, PFS: progression-free survival, RR: risk ratio, SGA: Subjective Global Assessment, T2DM: type 2 diabetes mellitus, VAI: visceral adiposity index, WD: well-differentiated,