Can neuroendocrine tumors cause nausea?

Neuroendocrine Tumors Can Cause Nausea

Yes, neuroendocrine tumors (NETs) can definitely cause nausea as a clinical symptom, both through direct obstructive effects and through hormone secretion. 1 This symptom may occur in both functioning and non-functioning NETs, though the underlying mechanisms differ.

Mechanisms of Nausea in NETs

1. Obstructive Effects

• Primary gastroenteropancreatic NETs can present with obstructive symptoms including pain, nausea, and vomiting, even when radiological findings appear normal 1
• Mass effects from the primary tumor or metastases (especially liver) can lead to non-specific symptoms including nausea and vomiting 1
• Intestinal NETs may cause bowel obstruction or mesenteric ischemia, both of which can manifest with nausea 1, 2

2. Hormone-Related Effects

• Functioning NETs secrete various bioactive substances (peptides and amines) that can trigger nausea 3
• Carcinoid syndrome, characterized by flushing, diarrhea, and sometimes wheezing, may be accompanied by nausea, particularly during flushing episodes 1
• Carcinoid crisis (a life-threatening complication) involves profound flushing, bronchospasm, tachycardia, and blood pressure fluctuations that can include severe nausea 1

NET Types Associated with Nausea

Bronchial Carcinoids

• 15% of patients with bronchial carcinoid tumors present with various symptoms including weakness, nausea, weight loss, night sweats, and neuralgia 1
• These symptoms may occur alongside more typical respiratory symptoms like cough and hemoptysis

Gastrointestinal NETs

• Small intestinal NETs (formerly called carcinoids) can cause nonspecific symptoms including nausea for extended periods before diagnosis 2
• Gallbladder NETs, though rare, commonly present with right upper quadrant pain and nausea 4

Pancreatic NETs

• Different types of pancreatic NETs can cause various clinical syndromes, some of which include nausea as a symptom 1
• Non-functioning pancreatic NETs may cause symptoms related to the pancreatic mass itself, including nausea 1

Clinical Implications

Diagnostic Challenges

• Nausea is a non-specific symptom that can lead to delayed diagnosis of NETs 2
• The presence of unexplained persistent nausea, especially when combined with other symptoms like flushing, diarrhea, or abdominal pain, should raise suspicion for NETs 1

Treatment Considerations

• Treating the underlying NET is essential for symptom relief, including nausea
• Surgical resection remains the mainstay of treatment when possible 3
• For unresectable disease, somatostatin analogs (octreotide and lanreotide) can help control hormone-related symptoms including nausea 3, 5
• Newer agents like telotristat etiprate may help control symptoms in carcinoid syndrome by inhibiting serotonin production 3

Important Clinical Pitfalls

• NETs are often misdiagnosed initially due to their nonspecific symptoms like nausea
• Nausea may be attributed to more common conditions, delaying proper diagnosis and treatment
• During procedures like surgery or tumor embolization, manipulation of the tumor can trigger carcinoid crisis with severe nausea and other life-threatening symptoms 1
• All patients with NETs should be evaluated for second endocrine tumors and possibly other gut cancers, as these may contribute to or complicate symptoms 1

Nausea in NET patients may require both tumor-directed therapies and symptomatic management for optimal quality of life and improved outcomes.