Neuroendocrine tumors (NETs) are most commonly found in the gastrointestinal tract. Sometimes asymptomatic, they can secrete abnormally high amounts of hormones that affect body functions and can cause digestive system problems, weight loss and flushing (redness of the skin and hot flushes). Learn more about this rare endocrine disease, its diagnosis and the different treatment options available.
GI-NETs often go unnoticed for several years, if there are no symptoms or only vague symptoms. Diagnosis is often late, the average delay being between five and seven years. As a result, by the time it is discovered, the tumor will have already spread in 20 to 50% of cases.
There are a number of tests available to aid diagnosis:
- Endoscopy or ultrasound endoscopy (where a tube with an ultrasound probe is used to see the walls of a cavity) can detect tumors inside the digestive tract and take biopsies.
- Scans and MRIs can locate the tumor, but cannot determine whether they are endocrine tumors.
- Nuclear medicine tests, such as scintigraphy and positron emission tomography (PET) scans, inject markers that attach to the NET receptors to confirm whether the tumor is an endocrine one.
- Blood tests can also be helpful in detecting functional NETs because of the abnormal increase in hormone secretion.
- Microscopic analysis of the tumor or a tumor sample is the only test to confirm the diagnosis. To do this, patients may be told that a tumor biopsy is needed, which means drawing a small sample of the tumor for examination under the microscope (histology).
people in the United States have1 GEP-NETs.
new cases per 100,000 people per year2
Around age 653
the average age at the time of diagnosis
1 Gastrointestinal Carcinoid Tumors: American Cancer Society Website: http://www.cancer.org/acs/groups/cid/documents/webcontent/003102-pdf.pdf. Accessed October 28, 2014
2 Niederle MB, Hackl M, Kaserer K, Niederle B. Gastroenteropancreatic neuro-endocrine tumours: the current incidence and staging based on the WHO and European Neuro-endocrine Tumour Society classifi cation: an analysis based on prospectively collected parameters. Endocr Relat Cancer 2010;17(4):909-18
3Lepage C, Bouvier AM, Phelip JM, Hatem C, Vernet C, Faivre J. Incidence and management of malignant digestive endocrine tumours in a well defi ned French population. Gut 2004; 53(4):549-53