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Gastrointestinal Carcinoid Tumor Risk Factors

A risk factor is anything that increases your chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, like smoking, can be changed. Others, like a person’s age or family history, can’t be changed. 

In some cases, there might be a factor that may decrease your risk of developing cancer. That is not considered a risk factor, but you may see them noted clearly on this page as well. 

But having a risk factor, or even many, does not mean that you will get cancer. And some people who get cancer may not have any known risk factors. Here are some of the risk factors known to increase your risk for GI carcinoid tumors.

Genetic syndromes

Multiple endocrine neoplasia, type I

This is a rare condition caused by inherited defects in the MEN1 gene. People with this syndrome have a very high risk of getting tumors of the pituitary, parathyroid, and pancreas. They also have an increased risk of carcinoid tumors. Some studies estimate that inherited mutations of the MEN1 gene are responsible for about 5% to 10% of carcinoid tumors. Most of these are gastric (stomach) carcinoids. Children have a 50/50 chance of inheriting this syndrome from a parent.

If you have family members with the MEN1 syndrome, you might want to talk to your doctor about the pros and cons of getting tested for it. Although the gene that causes tumors in people with the MEN1 syndrome has been found, the results of genetic testing are not always clear cut so it is important that the test is done along with genetic counseling to help you make sense of the results.

Neurofibromatosis type 1

This disease often runs in families and is characterized by many neurofibromas (benign tumors that form in nerves under the skin and in other parts of the body). It is caused by defects in the NF1 gene. Some people with this condition also develop carcinoid tumors of the small intestines.

Other genetic syndromes

Carcinoid tumors are also more common among people with tuberous sclerosis complex, von Hippel Lindau disease and familial small intestinal neuroendocrine tumor.

  • Tuberous sclerosis complex can be caused by a defect in the TSC1 or TSC2 gene. People with this condition can also develop tumors of the heart, eyes, brain, lungs, and skin.
  • People with von Hippel Lindau disease have an inherited tendency to develop blood vessel tumors of the brain, spinal cord, or retina, as well as kidney cancer. It is caused by changes in the VHL gene.
  • A newly discovered condition called familial small intestinal neuroendocrine tumor has been found which is caused by a change in the IPMK gene. People with this gene defect have a higher risk of developing carcinoid tumors in the small intestine (bowel).

To find out more on being tested for genetic syndromes, see Genetic Testing: What You Need to Know.

Race and sex

Carcinoid tumors are more common among African Americans than whites. Outcomes are also not as good for African Americans. Researchers do not yet know why. Carcinoid tumors are also slightly more common in women than men.

Other stomach conditions

People with certain diseases that damage the stomach and reduce the amount of acid it makes (such as atrophic gastritis or Zollinger-Ellison syndrome) have a greater risk of developing stomach carcinoid tumors, but their risk for carcinoid tumors of other organs is not affected.

Family history of any type of cancer 

Having a family history of any cancer, specifically in a first-degree relative (sibling, parent, or child), or a family history of a neuroendocrine tumor or carcinoid tumor seems to raise the risk of developing a carcinoid tumor.

Factors with uncertain or unproven effects


It is not clear if smoking increases the risk of getting a carcinoid tumor. Further studies are needed.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

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Last Revised: September 24, 2018

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