Would a ketogenic (keto) diet be beneficial for someone with a metastatic pancreatic neuroendocrine tumor (PNET) that has metastasized to the liver, following resection of the primary pancreatic tumor?

From the Guidelines

A keto diet may not be recommended for someone with metastatic pancreatic neuroendocrine tumors (NETs) that have spread to the liver, especially after primary tumor resection, due to the potential risk of malnutrition and insufficient energy intake. The ketogenic diet, which is high in fat, moderate in protein, and very low in carbohydrates, forces the body to use ketones rather than glucose for energy. However, according to the ESPEN guidelines on nutrition in cancer patients 1, dietary provisions that restrict energy intake in patients with or at risk of malnutrition should be avoided.

Key Considerations

• The guidelines recommend against all forms of diets that are not based on clinical evidence, have no proven efficacy, and that potentially could be harmful 1.
• A study published in 2024 compared international guidelines on the management of advanced non-functioning well-differentiated pancreatic neuroendocrine tumors, but did not provide specific recommendations on dietary interventions 1.
• Other studies have discussed the management of locoregional unresectable and/or metastatic neuroendocrine tumors of the pancreas, but have not addressed the use of ketogenic diets specifically 1.

Implementation and Supervision

To implement a keto diet, one would need to limit carbohydrates to approximately 20-50 grams daily, with 70-80% of calories coming from healthy fats and 15-20% from protein. However, this diet can cause side effects including fatigue, constipation, and potential nutrient deficiencies, which could be problematic during cancer treatment. Additionally, liver metastases may affect how your body processes fats, potentially making a high-fat diet challenging. Given the complexity of your condition, any dietary changes should be supervised by both an oncologist and a dietitian with experience in ketogenic diets for cancer patients.

Prioritizing Morbidity, Mortality, and Quality of Life

The primary concern in managing metastatic pancreatic NETs is to prioritize morbidity, mortality, and quality of life. While a keto diet may have potential benefits, the current evidence does not support its use in this context, and the potential risks of malnutrition and insufficient energy intake must be carefully considered. Therefore, it is essential to discuss any dietary changes with your oncology team before implementation.

From the Research

Keto Diet and Metastatic Pancreatic Neuroendocrine Tumors

• There is no direct evidence in the provided studies to suggest that a keto diet would be beneficial for someone with a metastatic pancreatic neuroendocrine tumor that has metastasized to the liver, where the primary tumor in the pancreas was resected 2, 3, 4, 5, 6.
• The studies focus on the management and treatment of metastatic pancreatic neuroendocrine tumors, including surgery, chemotherapy, and targeted therapies, but do not mention dietary interventions such as a keto diet 2, 3, 4, 5, 6.
• The treatment of metastatic pancreatic neuroendocrine tumors is complex and depends on various factors, including the tumor grade, stage, and location, as well as the presence of extra-hepatic or extra-abdominal disease 2, 3, 4, 5, 6.
• Surgery, including resection of the primary tumor and liver debulking, may be beneficial in select cases, but the decision to undergo surgery should be made on a case-by-case basis, taking into account the individual patient's characteristics and disease status 3, 6.
• The use of chemotherapy, targeted therapies, and other treatments may also be considered, depending on the patient's specific needs and circumstances 2, 4, 5.