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Desmoid Tumor

What is desmoid tumor?

Desmoid tumors grow from the connective tissue in your body. They grow from fibroblast cells, which make up connective tissue and are also important for wound healing. Connective tissue supports and connects your bones, ligaments, and muscles, and helps hold your organs in place. Desmoid tumors are also known as aggressive fibromatosis or desmoid-type fibromatosis.

A desmoid tumor can occur anywhere in the body since connective tissue is found everywhere in your body. Desmoid tumors are often found in the abdomen, as well as the shoulders, upper arms, and thighs.

Desmoid tumors are locally aggressive tumors. While the cells of the desmoid tumor do not travel to other parts of the body like cancer can, they can invade nearby tissue and are often very painful. Desmoid tumors can grow slowly or very quickly. The quicker they grow the more serious they are. Desmoid tumors can be difficult to completely remove with surgery.  

Desmoid tumors are most common in people between the ages of 15 and 60 years. They are more common in females than males.

How common is desmoid tumor?

For every one million people worldwide, two to four are diagnosed with a desmoid tumor per year.

How is desmoid tumor diagnosed?

Some people with desmoid tumors have symptoms, while others do not. Symptoms can include pain, swelling in the area of the tumor, sleep loss, or difficulty moving. For people without symptoms, these tumors can be discovered if the person has an imaging test for another reason.

Imaging: If you have symptoms of a desmoid tumor, your doctor may use imaging scans such as CT, MRI, or ultrasound to see where the tumor is and its size.

Biopsy: To check if the tumor is a desmoid tumor your doctor will do a biopsy, taking a small amount of the tumor out with a needle. A pathologist will study the cells under the microscope to see what kind of tumor it is. Depending on the tumor's location, it may be difficult for the doctor to take a biopsy.

How is desmoid tumor treated?

Treatment for each patient will be unique so you should go to an expert in sarcoma treatment to decide the best approach for your tumor. You can contact MyPART for help finding experts near you.

Desmoid tumors can be hard to predict. They can shrink and go away on their own, they can remain the same size, or they can grow quickly.

Treatment options to discuss with your doctor include:

Watch and wait: In some cases, the tumor grows very slowly, or even shrinks without any treatment. It may be safest for your doctor to check your tumor regularly without treating it.

Surgery: Surgery has been a standard treatment for desmoid tumors in the past but this may be changing. Given that the tumor often returns to the same location after surgery, doctors are looking for other treatment options.

Radiation therapy: Radiation therapy is a treatment option for some desmoid tumors. Given that radiation therapy can cause other cancers in the future, it is important to discuss alternatives with your doctor.

Chemotherapy: There is no standard chemotherapy for desmoid tumors but promising new drugs have been shown to shrink these tumors.

It is important to discuss these different options with your doctor and seek second opinions, if possible.

Do desmoid tumors run in families?

In 5% to 10% of cases, desmoid tumors may run in families. Those diagnosed with Gardner syndrome, a rare syndrome that also runs in families, have a high risk of colorectal cancer and desmoid tumor.

How does desmoid tumor form?

Scientists are always working to understand how tumors form but it can be hard to prove. We know that some people with a family history of desmoid tumors have a change in a gene called adenomatous polyposis coli, or APC. This change causes too much of a protein called beta-catenin in parts of your cells. Too much beta-catenin can cause cells to grow when they shouldn’t. In some desmoid tumors, there is too much beta-catenin, even though APC is normal.

APC and beta-catenin are important in many common cancers, such as colon cancer, and scientists are trying to use this information to develop better cancer treatments, which will help people with desmoid tumors.

What is the prognosis for someone with a desmoid tumor?

The estimate of how a disease will affect you long-term is called prognosis. Every person is different and prognosis will depend on many factors, such as:

  • Where the tumor is in your body
  • How fast the tumor grows
  • How much of the tumor was taken out during surgery

If you want information on your prognosis, it is important to talk to your doctor. NCI also has resources to help you understand cancer prognosis.

Doctors estimate desmoid tumor survival rates by how groups of people with desmoid tumors have done in the past. Given that there are so few desmoid tumor patients, survival rates may not be very accurate. They also don’t consider newer treatments being developed.

Most desmoid tumors do not impact lifespan but they are very difficult to get rid of and can be painful to live with. Desmoid tumors growing in the abdomen can cause problems, such as blocking your intestines. It is important that your doctor monitor the growth of these tumors carefully.