A risk factor is anything that affects your chance of getting a disease such as cancer. For example, exposure to strong sunlight is a risk factor for skin cancer, while smoking is a risk factor for cancer of the lung, and several other cancers. But risk factors don't tell us everything. Someone without any known risk factors can still develop cancer. And someone can have a risk factor, but still not get the disease. Only a few risk factors for GI carcinoid tumors are known, such as:

Genetic syndromes

Multiple endocrine neoplasia, type I: This is a rare condition caused by inherited defects in the gene MEN1. People with this syndrome have a very high risk of getting tumors of 3 glands: 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 10% of carcinoid tumors. Most of these are gastric (stomach) carcinoids. Children have a 50/50 chance of inheriting this syndrome from an affected parent.

If your family is affected by 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, genetic testing for MEN1 is only available in a few places at this time. Because the test is not always 100% accurate, it is important that the test is done along with genetic counseling to help 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 gene NF1. Some people with this condition also develop neuroendocrine tumors of the small intestines.

Race and gender

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 have a greater risk of developing stomach carcinoid tumors, but their risk for carcinoid tumors of other organs is not affected.

Factors with uncertain or unproven effects

Smoking

Smoking may double the risk of getting a carcinoid tumor of the small intestine, according to a recent European study. But further research is needed to confirm this.

Diet

Risk of developing GI carcinoid tumors does not appear to be increased or decreased by any specific foods.

Last Medical Review: 06/19/2009
Last Revised: 06/19/2009