Nutritional Support for Gastrointestinal Cancer Patients: New (and Old) Frontiers in Management, a Narrative Review

Malnutrition in patients with gastrointestinal (GI) cancers can be the result of functional and/or anatomical changes in the alimentary tract, secondary to malignancy or oncologic therapies. Understanding the underlying mechanisms of malnutrition in these patients is imperative in providing appropriate interventions that can not only improve quality of life for these individuals, but also improve their tolerance of oncologic treatment and progression towards remission or cure. In this narrative review, we address common nutritional deficiencies associated with GI malignancies, including pancreatic, biliary, and hepatic cancers. Furthermore, we address common issues related to these deficiencies and causes of nutrition barriers as they relate to organ malfunction or surgical alterations of anatomy. Recommendations for counseling, dietary modifications, nutritional supplements, and pharmacologic interventions are provided based on individual barriers and the vital role of multidisciplinary care is highlighted. Additionally, we highlight novel techniques, such as the role of psychosocial care, prehabilitation, digital health, and machine learning, which can improve nutritional outcomes, provide patient-directed care, and improve risk stratification for this complex and multifaceted issue that faces patients diagnosed with GI cancers.