What Are Neuroendocrine Tumors?
Neuroendocrine tumors (NETs) are rare cancers that develop from neuroendocrine cells, specialized cells found throughout the body that help regulate important functions by releasing hormones. These cells are present in many organs, including the gastrointestinal tract, pancreas, lungs, and other parts of the body.
Some neuroendocrine tumors grow slowly and may not cause symptoms for years. Others are more aggressive and can spread to nearby tissues or distant organs. Because NETs can develop in many locations and behave differently from one patient to another, specialized care is important for accurate diagnosis and treatment.
At the GW Cancer Center, our multidisciplinary team works together to provide personalized care for patients with neuroendocrine tumors, using advanced diagnostic tools, innovative therapies, and access to clinical trials.
Types of Neuroendocrine Tumors
Neuroendocrine tumors can develop in several areas of the body, including:
- Gastrointestinal neuroendocrine tumors (GI NETs), which occur in the stomach, small intestine, colon, rectum, or appendix
- Pancreatic neuroendocrine tumors (pNETs)
- Lung neuroendocrine tumors
- Neuroendocrine tumors of unknown primary origin
NETs may also be classified as:
Functional Neuroendocrine Tumors
Functional tumors produce excess hormones that can cause noticeable symptoms, such as flushing, diarrhea, low blood sugar, or stomach ulcers.
Nonfunctional Neuroendocrine Tumors
Nonfunctional tumors do not release excess hormones and often cause symptoms only when they grow large enough to affect nearby organs.
Well-Differentiated Neuroendocrine Tumors
These tumors tend to grow more slowly and generally have a more favorable prognosis.
Poorly Differentiated Neuroendocrine Carcinomas
These tumors are more aggressive and may require intensive treatment.
Risk Factors
The exact cause of most neuroendocrine tumors is unknown. Factors that may increase risk include:
- Increasing age
- Family history of neuroendocrine tumors
- Certain inherited genetic syndromes, such as Multiple Endocrine Neoplasia Type 1 (MEN1)
- Von Hippel-Lindau syndrome
- Neurofibromatosis type 1
- Tuberous sclerosis complex
Having one or more risk factors does not mean a person will develop a neuroendocrine tumor.