Neuroendocrine Tumours (NETs)

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This blog is for informational purposes only and should not be taken as medical advice. Content is sourced from third parties, and we do not guarantee accuracy or accept any liability for its use. Always consult a qualified healthcare professional for medical guidance.

What is Neuroendocrine Tumours (NETs)?

Neuroendocrine tumours (NETs) are rare cancers arising from neuroendocrine cells, which release hormones in response to nerve signals, located throughout the body but commonly in the gastrointestinal tract (60%), lungs (25%), or pancreas (7%). NETs are graded 1-3 based on proliferation (Ki-67 index): grade 1 (low, <3%) are slow-growing, grade 3 (high, >20%) aggressive like neuroendocrine carcinoma (NEC). Functional NETs (30%) secrete hormones causing syndromes (e.g., carcinoid), while non-functional are silent. In 2025, ~12,000 US cases annually, median age 60, with increasing incidence due to better detection.

Symptoms

Symptoms vary by location and functionality. Non-functional NETs cause abdominal pain, bowel obstruction, weight loss, or jaundice (liver involvement). Functional NETs produce hormone excess: carcinoid syndrome (flushing, diarrhea, wheezing from serotonin), Zollinger-Ellison (ulcers from gastrin), insulinoma (hypoglycemia from insulin), or VIPoma (diarrhea from VIP). Lung NETs cause cough, wheezing, or hemoptysis. Symptoms are often vague, delaying diagnosis by 5-7 years.

Causes

Causes include genetic mutations (MEN1, VHL syndromes in 10%), with sporadic NETs linked to smoking (lung NETs), chronic inflammation, or diabetes. Familial syndromes increase risk. In 2025, mutations in DAXX/ATRX (pancreatic NETs) and SDHx (pheochromocytoma/paraganglioma) are key, with no strong lifestyle causes except smoking.

Diagnosis

Diagnosis uses blood/urine tests for hormone markers (chromogranin A, 5-HIAA), imaging (CT/MRI, somatostatin receptor scintigraphy like Ga-68 DOTATATE PET for receptor-positive NETs), and endoscopy/bronchoscopy for biopsy. Functional tests assess hormone levels. In 2025, AI and molecular profiling improve grading and origin detection.

Treatment

Surgery cures localized NETs (resection/endoscopic removal). Advanced cases use somatostatin analogs (octreotide, lanreotide) for symptom control/growth inhibition, peptide receptor radionuclide therapy (PRRT, lutetium-177 dotatate, 70% response), chemotherapy (for grade 3), or targeted therapy (everolimus for mTOR, sunitinib for pancreatic). Liver embolization palliates hepatic metastases. In 2025, biological treatments and immunotherapy trials advance care.

Future Outlook

In 2025, 5-year survival is 60-90% for localized, 20-50% for metastatic, with grade 1 NETs often indolent. PRRT and targeted therapies extend survival by 2-3 years. Research on immunotherapy (checkpoint inhibitors) and gene therapies could improve metastatic survival to 60% by 2030, with focus on early detection.

Sources

The information for neuroendocrine tumours (NETs) is sourced from Cleveland Clinic’s “Neuroendocrine Tumors (NETs): Symptoms & Treatment” for symptoms and treatment; OncoDaily’s “Neuroendocrine Tumors: The Silent Cancer on the Rise” for 2025 outlook; PMC’s “Treatment strategies for advanced neuroendocrine neoplasms” for treatment; Penn Medicine’s “Neuroendocrine Tumors (NETs) – Symptoms and Causes” for causes; Mayo Clinic’s “Neuroendocrine tumors – Symptoms and causes” for symptoms; MD Anderson’s “Neuroendocrine Tumor Treatment” for treatment; ScienceDirect’s “Current perspectives on neuroendocrine tumors” for perspectives; Duke Health’s “Neuroendocrine Tumors (NETs)” for overview; City of Hope’s “Neuroendocrine Tumors: Symptoms” for symptoms; Dana-Farber’s “Research Breakthroughs for Neuroendocrine and Carcinoid Tumors” for research.