GoodRx Guide
Neuroendocrine Tumors
Comprehensive information for you or a loved one — including treatment options and discounts on popular medications.
Definition
Neuroendocrine tumors are a rare type of cancer. They begin in neuroendocrine cells, a type of specialized cell. Neuroendocrine tumors are also sometimes called:
Neuroendocrine neoplasms
Carcinoid tumors
Neuroendocrine cells are found in many different organs. They play an important role in how different parts of the body work together.
Their job is to make and release hormones in response to signals from nerve cells. The hormones made by neuroendocrine cells travel to different parts of the body and help regulate things like:
Digestion
Blood pressure and heart rate
Blood sugar levels
Muscle and bone growth
Air and blood flow through the lungs
There are neuroendocrine cells all over the body. So neuroendocrine tumors can develop in many places, including the lungs, small intestines, and pancreas.
Symptoms
Some people with neuroendocrine tumors don’t experience any symptoms. In these situations, people often find out they have these tumors by chance. This can happen when the tumor is picked up by a study that was ordered for another reason. For example, some people find out they have a neuroendocrine tumor in their intestine during a routine colonoscopy.
But some people do develop symptoms when they have a neuroendocrine tumor. Symptoms will look very different from person to person. The symptoms of neuroendocrine tumors depend on the size of the tumor, its location, and the type of hormone production (if any).
Tumor location
As a tumor grows, it can cause swelling, which people may notice as a lump. A growing tumor also presses on surrounding structures, which can cause pain or dysfunction in the area.
For example, a neuroendocrine tumor in the lungs can put pressure on respiratory structures and lung tissue. And this can cause symptoms like cough or hoarseness. A neuroendocrine tumor in the gastrointestinal (GI) tract may cause abdominal pain or changes in bowel and bladder habits.
Hormone production
Neuroendocrine tumors can make hormones, just like healthy neuroendocrine cells. But tumor cells don’t respond to normal signals that turn hormone production on and off. That means they can make too much of a specific hormone, and those extra hormones will trigger specific symptoms.
For example, if a neuroendocrine tumor makes a hormone that overstimulates insulin production, people can develop low blood sugar and symptoms like dizziness, sweating, fainting, and seizures.
Diagnosis
Diagnosing a neuroendocrine tumor can be challenging. Most people need a mix of studies to figure out whether they have a neuroendocrine tumor.
Some studies that can help diagnose a neuroendocrine tumor include:
Blood tests: These can measure electrolytes, blood sugar, and liver and kidney function. There are also special blood tests that measure hormone levels and look for evidence of a tumor activity (NETEST). And a urine test can measure certain hormone levels (5-HIAA test).
Imaging studies: These studies can look for tumors and possible spread. They include CT and MRI scans as well as more specialized studies, like PET scans and somatostatin receptor scintigraphy (octreotide scans).
Endoscopy studies: These studies use a camera to look for evidence of a tumor. This includes upper GI endoscopy, colonoscopy, and bronchoscopy.
Tissue tests: This can include a biopsy of a suspected tumor. The tissue removed during a biopsy is then examined under a microscope for signs of a neuroendocrine tumor.
Treatments
Treatment for neuroendocrine tumors is highly individualized and depends on:
The tumor’s location and size
Whether the tumor makes hormones
Whether the tumor has spread to other parts of the body
Most people need a combination of therapy to treat their neuroendocrine tumors. This can include:
Surgery to remove the tumor
Somatostatin analogs, a medication that stops the tumor from making too many hormones and can slow tumor growth
Target therapy, medications that kill cancer cells by attacking genes or proteins on cancer cells
Traditional chemotherapy medications
Medications to help manage symptoms of neuroendocrine tumors, like diarrhea
Experts recommend that people with neuroendocrine tumors receive their care at a center with expertise in managing these tumors. This gives people the best access to specialists, support, and clinical trials. You can find these specialized centers using a tool from the Neuroendocrine Tumor Research Foundation.
Frequently asked questions
How long you live with a neuroendocrine tumor depends on:
The size and location of the tumor
How different the tumor cells are from normal neuroendocrine cells (“differentiation”)
How fast the tumor is growing
Whether the tumor has spread to other parts of of the body (“metastasis”)
Each person’s prognosis will be different depending on these factors. In general, people live longer when their tumor is found early, before it’s had a chance to grow or spread.
For example, the 5 year survival rate for people with early neuroendocrine tumors ranges from 65% to 90% depending on where the tumor is.
Sometimes. Researchers still don’t know why neuroendocrine tumors develop. But people with certain genetic conditions are more likely to develop this type of cancer. And some of these genetic conditions run in families. For example, people with multiple endocrine neoplasia type 1 or 2 (MEN-1 or MEN-2) and neurofibromatosis are more likely to develop neuroendocrine tumors.
People can develop neuroendocrine tumors at any age. But neuroendocrine tumors are not common in children and young adults. Most people diagnosed with neuroendocrine tumors are between 50 and 60 years old.
References
Canadian Cancer Society. (n.d.). Survival statistics for neuroendocrine tumours (NETs).
Cancer.net. (2019). Multiple endocrine neoplasia type 1.
Cancer.net. (2022). Neuroendocrine tumors: Symptoms and signs.
Demarco, C. (2020). 9 things to know about neuroendocrine tumors.
Gut, P., et al. (2015). Familial syndromes associated with neuroendocrine tumours. Contemporary Oncology.
Macmillan Cancer Support. (2022). Neuroendocrine tumours (NETs).
National Cancer Institute. (2022). Targeted therapy to treat cancer.
Neuroendocrine Tumor Research Foundation. (n.d.). Diagnostics tests.
