There are tumors in the brain and the surrounding tissues. Your body has special cells. hormones are released into your blood when you receive messages from your nervous system.

It’s estimated that about 12,000 people are diagnosed with neuroendocrine tumors each year in the United States. They can develop anywhere in your body, but the most common place is your digestive tract.

Factors such as size and Aggressive. of the tumors, as well as what organ they develop in, affect the symptoms and outlook for them. Learn more about these rare cancers.

Neuroendocrine tumors develop in neuroendocrine cells. These cells are found in almost every organ of your body. Their function is to release hormones in response to signals from your nerves. For example, neuroendocrine cells in your adrenal glands release the hormone epinephrine (adrenaline) in response to stress.

Previously, neuroendocrine tumors were classified as cancerous or noncancerous, but now all neuroendocrine tumors are considered cancer.

Neuroendocrine tumors can either be classified as functioning or nonfunctioning:

  • Excess hormones are produced by tumors that cause symptoms.
  • “Excess hormones are not produced by tumors that don’t cause symptoms.”

The number of neuroendocrine tumors diagnosed each year in the United States is steadily increasing, likely due to better detection.

Carcinoid tumors vs. neuroendocrine carcinoma

The term carcinoid usually refers to low- or intermediate-grade neuroendocrine tumors with well-differentiated cells, meaning the cells look normal under a microscope.

The term is used for tumors that are high in grade. These tumors are less common than the others.

Neuroendocrine tumors can develop in almost any organ but are most common in your digestive tract.

The next most common place for these tumors to develop is your lungs. About 30 percent of endocrine tumors develop in your lungs. About 7 percent develop in the pancreas.

Roughly 15 percent of neuroendocrine tumors are found outside the gastrointestinal tract, pancreas, or lungs.

Where neuroendocrine tumors are likely to develop. Illustration by Yaja Mulcare.

The signs and symptoms of tumors vary depending on where the tumors are. Other factors that determine symptoms include:

  • The size of the tumor.
  • The type of tumors.
  • The cancer produces hormones.
  • Whether it has spread to distant parts of your body.

“People with tumors of the brain don’t have symptoms until the tumor is large enough to affect organ function.”

Symptoms can be categorized into:

  • hormonal: Excess hormones produced by the tumor can cause symptoms such as poor blood sugar control, diarrhea, or gastric ulcers, depending on where the tumor forms.
  • mechanical: The tumor can cause symptoms by putting physical pressure on an organ. For example, a tumor in your intestines may cause bowel obstruction.

Symptoms of gastrointestinal tumors

Here are some of the typical symptoms of tumors affecting the gastrointestinal system or pancreas:

Symptom Percentage of cases
abdominal pain 28 to 79
bowel obstruction 18 to 24
diarrhea 10 to 32
carcinoid heart disease 8 to 19
flushing 4 to 25
bleeding in gastrointestinal tract 5 to 10
incidental (a finding that appears during a routine scan or when diagnosing another ailment) 9 to 18

Symptoms of lung tumors

The main symptoms for lung tumors are listed.

Symptom Percentage of cases
cough 5 to 27
coughing up blood 23 to 32
recurrent respiratory infections 41 to 49
incidental (a finding that appears during a routine scan or when diagnosing another ailment) 17 to 39

Some people develop tumors that are not entirely clear to researchers. People with no family history are more likely to have tumors.

Some genetic cancer syndromes increase your risk. These include:

  • Multiple neoplasia type 1 is a type of neoplasia.
  • Von Hippel-Lindau disease is a disease.
  • Tuberous Sclerosis is a disease.
  • There is a type offibromatosis.

If you get the genes from one parent, you will develop these conditions.

Other risk factors include:

  • race: White people have a higher risk than Black people of developing neuroendocrine tumors overall, but the risk varies between specific types.
  • gender: Women develop neuroendocrine tumors slightly more often than men.
  • age: Neuroendocrine tumors are rare in childhood.
  • certain medical conditions: Some medical conditions may put you at an increased risk of developing certain types of neuroendocrine tumors. For example, reduced stomach acid production increases the risk of neuroendocrine tumors in the stomach.

“Symptoms of tumors are often nonspecific. A nonspecific symptom is something that a person can’t be observed by a doctor. Chronic fatigue or pain unrelated to an injury are examples.”

Neuroendocrine tumors may be found incidentally while testing for other conditions. One survey of 1,928 people found an average delay of 52 months between symptom onset and diagnosis.

To confirm diagnosis, doctors may use a number of different tests, including:

  • Blood tests.
  • urine tests
  • It is a medical procedure.
  • A small tissue sample is being taken for a biopsy.

The tests may include:

Treatment for tumors of the brain depends on factors.

  • The location of the tumor.
  • Aggressive.
  • How advanced the cancer is.
  • Your overall health.
  • The tumor is producing hormones.

Neuroendocrine tumors usually grow slowly when they’re in your gastrointestinal tract or appendix.

Active surveillance

If the tumor is not growing fast, your doctor may recommend active vigilance. You are not given specific treatment with active surveillance.

Surgery with or without chemotherapy or radiation therapy

If the tumor has not spread beyond the organ of origin, it may be removed. Radiation therapy can be used to shrink tumors.

A form of internal radiation therapy called peptide receptor radionuclide therapy was FDA-approved in 2018 to treat advanced gastrointestinal and pancreatic neuroendocrine tumors.


Your doctor may recommend medications called somatostatin analogs such as octreotide or lanreotide.

The medications may help you with symptoms. They are usually injected every 28 days.

The American Cancer Society uses information from the SEER database to track survival rates for tumors. A relative survival rate is the percentage of people who survive a tumor compared to the population as a whole.

“The table below shows the 5-year relative survival rates. They don’t take into account your age, overall health, and how well your cancer is responding to treatment People being diagnosed with cancer today may have a better outlook because treatments improve over time.”

It is always best to discuss your outlook with your doctor. They can give you a more accurate understanding of the numbers, and know more about your situation.

5-year relative survival rates for neuroendocrine tumors

SEER stage Gastrointestinal tumors Pancreatic tumors Lung tumors
localized 97% 93% 98%
regional 95% 74% 87%
distant 66% 24% 58%

Most of the tumors that form in your body are found in your lungs, stomach, and pancreas.

Symptoms can vary depending on where the tumor is. If the tumor produces excess hormones, they can cause problems.

If you suspect you have a cancer, it is important to visit your doctor as soon as possible. Cancer treatment is most effective when it is in the early stages.