Desmoid Tumor: Risk Factors

Approved by the Cancer.Net Editorial Board, 11/2022

ON THIS PAGE: You will find out more about the factors that increase the chance of developing a desmoid tumor. Use the menu to see other pages.

What are the risk factors for a desmoid tumor?

A risk factor is anything that increases a person’s chance of developing a tumor. Although risk factors often influence the development of a tumor, most do not directly cause a tumor. Some people with several risk factors never develop a tumor, while others with no known risk factors do. Knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.

There are no known causes for desmoid tumors. However, the following risk factors may increase a person’s chance of developing a desmoid tumor:

  • Sex. Desmoid tumors are slightly more common in women than in men.

  • Pregnancy: Desmoid tumors may form around or during the time of pregnancy. Pregnancy-associated desmoid tumors usually develop in the wall of the abdomen. The tumors may be related to the stretching of the abdominal wall during pregnancy, high levels of estrogen that occur during pregnancy, or both.

  • Familial adenomatous polyposis. People with a rare, inherited disease called familial adenomatous polyposis (FAP) have a high risk of desmoid tumors and colorectal cancer. This is sometimes called Gardner syndrome. The desmoid tumors that develop in people with FAP are often intra-abdominal tumors. Approximately 10% to 20% of people with FAP develop a desmoid tumor. Desmoid tumors are the second most common cause of death in people who have FAP. They cause about 9% to 11% of deaths in people with FAP. Certain people diagnosed with a desmoid tumor, particularly in the intra-abdominal area, may need to be screened for FAP.

  • Trauma to the body. Some research shows that serious or repeated trauma to the body, such as surgery or a severe injury, may increase the risk of developing a desmoid tumor at the site of injury, such as in a scar.

The next section in this guide is Symptoms and Signs. It explains what changes or medical problems a desmoid tumor can cause. Use the menu to choose a different section to read in this guide.