Neuroendocrine Tumors (NETs)

Types of Neuroendocrine Tumors (NETs)

NETs are categorized based on their location in the body and whether they produce hormones. Common types include:

• Gastrointestinal (GI) NETs: Found in the stomach, small intestine, colon, and rectum.
• Pancreatic NETs (pNETs): Arise in the pancreas; examples include insulinomas and gastrinomas.
• Lung NETs: Include typical and atypical carcinoid tumors in the lungs.
• Other NETs: Less common types may develop in the thyroid (medullary thyroid cancer), adrenal glands (pheochromocytoma), and other rare sites.

Functional vs. Non-Functional NETs

• Functional NETs: These produce excess hormones and may cause symptoms such as flushing, diarrhea, low blood sugar, or stomach ulcers.
• Non-Functional NETs: These do not produce hormones and often grow silently, becoming noticeable only when they enlarge or metastasize.

Who is at Risk for NETs?

• Genetic Conditions: Inherited syndromes such as Multiple Endocrine Neoplasia type 1 (MEN1), Von Hippel-Lindau (VHL), and Neurofibromatosis type 1 (NF1) can increase the risk of developing NETs.
• Chronic Stomach Problems: Conditions like long-term acid reflux or chronic atrophic gastritis may elevate the risk of developing gastric neuroendocrine tumors.
• Smoking: Associated with a higher risk of developing lung NETs, especially atypical carcinoids.

Treatment Options for Neuroendocrine Tumors

1. Surgery – The Best Chance for Cure

• If the tumor is small and localized, surgery can completely remove it and offer a potential cure.
• In advanced cases, surgery may still help relieve symptoms and reduce tumor burden.

2. Medications to Control Symptoms & Slow Growth

• Somatostatin Analog Injections (Octreotide, Lanreotide): Help control hormone-related symptoms and slow tumor progression.
• Targeted Therapy (Everolimus, Sunitinib): Used mainly for advanced pancreatic NETs to block tumor growth pathways.
• Peptide Receptor Radionuclide Therapy (PRRT): A form of targeted radiation therapy that binds to tumor cells and delivers radiation directly.

3. Chemotherapy – Used for Fast-Growing NETs

• Chemotherapy is typically reserved for aggressive, poorly differentiated NETs to help shrink tumors and slow progression.

4. Liver-Directed Therapy (For Liver Spread)

• Radiofrequency Ablation (RFA) and Embolization are local treatments that target NETs which have spread to the liver, helping to control symptoms and tumor growth.