A risk factor is any factor that is associated with an increased chance of developing a particular health condition, such as neuroendocrine cancer. There are different types of risk factors, some of which can be modified and some that cannot.

It should be noted that having one or more risk factors does not mean a person will develop neuroendocrine cancer. Many people have at least one risk factor but will never develop neuroendocrine cancer, while others with neuroendocrine cancer may have had no known risk factors. Even if a person with neuroendocrine cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease.

Risk factors for neuroendocrine cancer are not well understood. They include:

• certain rare hereditary conditions that can cause tumours to form in the body – multiple endocrine neoplasia (MEN), Von Hippel–Lindau disease, tuberous sclerosis and neurofibromatosis
• a family history of any type of cancer.

Some other factors have been linked with neuroendocrine cancer, but it is not yet known whether they are risk factors. These are:

• smoking
• chronic atrophic gastritis (a long-term condition that makes the lining of the stomach inflamed or swollen)
• diabetes.

Most cases of neuroendocrine cancer occur in people aged 60 years or older.