Gastrointestinal Neuroendocrine 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.

In some cases, there might be factors that may decrease your risk of developing cancer. Those are not considered risk factors, 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 neuroendocrine 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 neuroendocrine tumors. Some studies estimate that inherited mutations of the MEN1 gene are responsible for about 5% to 10% of neuroendocrine tumors. Most of these are gastric (stomach) neuroendocrine tumors . 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 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

Neurofibromatosis type 1 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 neuroendocrine tumors in the small intestine.

Other genetic syndromes

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

• 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 inherit a 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 is caused by a change in the IPMK gene. People with this gene defect have a higher risk of developing neuroendocrine 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

Neuroendocrine tumors are more common among Black people and African Americans than White people. Outcomes are also not as good for Black people and African Americans. Researchers do not yet know why neuroendocrine tumors are also slightly more common in women than in men.

Age

The average age at diagnosis is 55 to 65. Children rarely develop GI neuroendocrine tumors.

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 gastric neuroendocrine tumors, but their risk for neuroendocrine tumors of other organs is not affected.

Family history of any cancer

Having a family history of a neuroendocrine tumor seems to raise the risk of developing a neuroendocrine tumor.

Factors with uncertain or unproven effects

Smoking

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