Definition
Neuroendocrine tumors (NETs) are rare, typically slow-growing tumors that originate from neuroendocrine system cells. They occur in various organs, most commonly the gastrointestinal tract, pancreas, and lungs.
Pathogenesis
NETs arise from cells with both nervous and endocrine functions. Risk factors include:
- Genetic syndromes: Such as multiple endocrine neoplasia type 1 (MEN1).
- Chronic inflammation: E.g., chronic gastritis.
The tumors may be functional (secreting hormones and causing syndromes like carcinoid syndrome) or non-functional.
Diagnosis
Diagnosis is based on:
- Laboratory tests: Detection of specific markers like chromogranin A (CgA) and hormones (e.g., serotonin, gastrin).
- Imaging methods: CT, MRI, and PET-CT with Ga-68 DOTATATE for localization and staging.
- Biopsy: Confirms diagnosis and histological grade (differentiation and Ki-67 expression).
Treatment
Treatment depends on the tumor’s location, functionality, and spread:
- Surgical removal: The treatment of choice for localized disease.
- Somatostatin analogs: (e.g., octreotide) to manage functional tumors and control growth.
- Targeted therapies: (e.g., everolimus, sunitinib) for advanced stages.
- Peptide receptor radionuclide therapy (PRRT): Used in functional tumors with positive somatostatin receptors.
- Chemotherapy: For poorly differentiated, fast-growing tumors.
Prevention
Prevention includes managing predisposed conditions and closely monitoring individuals with genetic predisposition.
Early diagnosis and individualized therapeutic approaches significantly improve prognosis and quality of life, given the varied behavior of NETs.