Desmoid tumor (patient information)

Desmoid tumor commonly develops by division of myofibroblast cells in the fibrous (connective) tissue of the body that forms tendons and ligaments, usually in the arms, legs, abdomen, head and neck or any part of the body. These tissues of the body connect, support, and surround other body parts and organs.

• 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
• They can also be found in the shoulders, upper arms, and thighs
• Desmoid tumors are benign, which means they are not cancer
• While the cells of the desmoid tumor do not travel to parts 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

Out of one million people worldwide, two to four are diagnosed with a desmoid tumor per year

• Some people with desmoid tumors have symptoms, but others don’t
• Symptoms can include:
  • Pain
  • Swelling in the area of the tumor
  • Sleep loss
• Difficulty moving
• For people without symptoms, these tumors can be discovered if the person has an imaging test for another reason

• 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 how big it is

• 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
• An expert, called a pathologist, will study the cells under the microscope to see what kind of tumor it is
• Depending on where the tumor is in the body, it may be difficult for the doctor to take a biopsy

• Treatment for each patient will be unique
• 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
    • In this case 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
    • Because 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
    • Because radiation therapy can cause other cancers in the future, it is important to discuss 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

• In 5% to 10% of cases, desmoid tumors may run in families
• Gardner syndrome is a rare syndrome that runs in families
• People with this syndrome have a high risk of colorectal cancer and desmoid tumor

• 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

• 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
• Because there are so few desmoid tumor patients these rates may not be very accurate
• They also don’t take into account newer treatments being developed
• Most desmoid tumors don’t change how long you will live, 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

NATIONAL CANCER INSTITUTE – CANCER.GOV https://www.cancer.gov/nci/pediatric-adult-rare-tumor/rare-tumors/rare-soft-tissue-tumors/desmoid-tumor