Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, exposure to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes. Risk factors for appendix cancer are behaviours and characteristics that may increase the likelihood that an individual develops the condition. Many people who have more than one risk factor never develop the condition. While some people who get appendiceal tumours have no known risk factors.

Experts do not yet know exactly what causes appendix cancer. They have not discovered any links between the appendix and genetic or environmental causes. Doctors mostly believe that appendix tumour affects males and females equally. Because it is rare in children, being an adult is the only known risk factor.

To date, scientists have identified the following possible appendix risk factors:

Smoking: Smokers are more likely to develop appendix cancer than non-smokers.

Family history: Patients with a relative who has or has had appendix cancer or multiple endocrine neoplasia type 1 (MEN1) syndrome (also known as endocrine adenomatosis or Wermer syndrome) have a higher risk.

Medical history: Those with a history of certain medical conditions that affect the stomach's ability to produce acids, such as atrophic gastritis, pernicious anaemia, and Zollinger-Ellison syndrome, are at an increased risk for appendix cancer.

Gender: Women are more likely to develop carcinoid tumours than men.

Age: The average age at diagnosis is 40.