Desmoid tumours are rare soft tissue tumours. They are also known as aggressive fibromatosis or desmoid-type fibromatosis. Desmoid tumours are non-cancerous, or benign, growths that can grow into and affect vital organs. These tumours don’t spread, or metastasize, to other parts of the body.
There are 3 subtypes of desmoid tumours. Each subtype is related to different risk factors.
The first subtype occurs in the general population. There is no clear link between specific genes and the development of these tumours, so they are called sporadic desmoid tumours.
The second subtype is linked with pregnancy.
The third subtype is linked with familial adenomatous polyposis (FAP). FAP is an inherited disease that causes a large number of polyps to form in the colon and rectum. People with FAP may develop many different types of tumours, usually in the abdominal cavity. Desmoid tumours are the second most common type of tumour that develop in people with FAP.
A desmoid tumour is a firm, smooth, movable lump. It can occur anywhere in the body, but they commonly develop in the:
- abdomen or abdominal wall
- retroperitoneum (back of the abdomen)
- chest wall
- head and neck area
- arms and legs
Diagnosing desmoid tumours usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and will do a physical exam. Based on this information, your doctor may refer you to a specialist or order tests to check for desmoid tumour or other health problems. Tests may include:
- CT scan
Find out more about these tests and procedures.
Treatment options for desmoid tumours depend on where the tumour develops and whether or not it is growing. Different types of desmoid tumours grow at different rates. About 20% of desmoid tumours shrink and go away without any treatment. This is called spontaneous regression.
Because some desmoid tumours can go away on their own, doctors tend to closely monitor the tumour for a period of time to see if it is growing. This approach is called active surveillance. Surgery used to be the primary treatment, but many clinics that specialize in treating soft tissue sarcomas now use active surveillance to make sure the tumour needs to be removed.
Treatments are often given in clinics that specialize in treating soft tissue sarcomas. Doctors at these clinics have different specialties and are experienced treating this type of tumour.
You may be prescribed a drug to try to stop the tumour from growing. You could be prescribed nonsteroidal anti-inflammatory drugs (NSAIDs), hormone therapy or low-dose chemotherapy to treat your desmoid tumour.
NSAIDs, such as sulindac (Clinoril) or celecoxib (Celebrex), may be used for slow-growing desmoid tumours. These drugs help control pain and reduce inflammation or swelling.
Certain hormones, particularly estrogen, can make some desmoid tumours grow. Anti-estrogen drugs, such as tamoxifen (Nolvadex, Tamofen), are sometimes used to treat desmoid tumours. Women with tumours that are sensitive to estrogen should stop taking oral contraceptives or any other source of extra hormones. They should use another form of birth control, such as IUD.
Chemotherapy may be used if a desmoid tumour continues to grow after other treatments or if it doesn’t respond to other drug therapies. Chemotherapy combinations used to treat desmoid tumours are:
- methotrexate and vinblastine (Velbe)
- doxorubicin (Adriamycin), dacarbazine (DTIC) and carboplatin (Paraplatin, Paraplatin AQ)
In certain cases, your healthcare team may offer surgery to remove a desmoid tumour. Surgery is usually only used for tumours that are growing quickly or that cause pain or other symptoms. Tumours often come back, or recur, after surgery to remove the primary tumour.
External beam radiation therapy may be used before or after surgery. It may also be used instead of surgery in some cases.