What are Desmoids?

Desmoid tumors arise from connective tissue - the cells involved with the formation of muscle, fibrous and nerve tissue. Desmoid tumors, also called aggressive fibromatoses, are locally aggressive. This means that they can grow into and even destroy adjacent normal tissues, even bones. They do not, however, have the capacity to spread distantly (metastasize) throughout the body. Hence, most doctors consider desmoid tumors to be benign and not malignant. But regardless of the name, tumor-related destruction of vital structures and/or organs can be fatal.

Official WHO definition of Desmoids (2002): Clonal fibroblastic/myofibroblastic proliferation arising in the deep soft tissues characterized by infiltrative growth and tendency toward local recurrence but inability to metastasize.


A biopsy specimen is necessary to diagnose a desmoid tumor. Ultrasound is often the first method of examination of a soft tissue tumor. If the mass is solid, a CT and/or MRI scan is used to determine whether it adheres to nearby structures and whether it can be safely removed. A variety of options are available for biopsying a suspected desmoid: a core needle biopsy takes a small piece, usually 1 mm wide by 10 mm long; surgical biopsies may take a portion of the tumor (“incisional biopsy”) or may remove all the visible tumor (“excisional biopsy”). While an excisional biopsy may remove all visible tumor, it rarely completely removes all microscopic traces of the tumor – usually leaving a positive margin, that is, tumor at the edge of the biopsy site.



Desmoid tumors are surgically removed when feasible. The goal is to attempt to obtain tumor-free margins while preserving function and cosmesis. Desmoid tumors can have a high rate of recurrence with surgery alone. While statistics vary, as many as 25 to 40 percent of patients who undergo surgery can have a local recurrence, that is, return of the desmoid at or near the original site. However, when they recur, treatment with radiation and/or repeat surgery may be successful.


Radiation therapy (RT) is an effective option for many patients who cannot have surgery, or as an adjunct to surgery or chemotherapy. The duration of radiation treatment typically is 6 to 8 weeks. Radiographic evidence of tumor shrinkage may take months to years to become apparent. RT is often not considered an option in intraabdominal tumors because of the size of the area needed to be irradiated and the risk of radiation damage to vital structures.

Medical therapy

There is no single accepted medical treatment for desmoid tumors. Numerous reports of individual cases show shrinkage or stabilization of tumor size or at least improvement in symptoms after a very wide variety of treatments. Patients with desmoid tumors have been treated with non-steroidal anti-inflammatory drugs (NSAIDs).

Clear evidence suggests the hormonal dependency of some desmoid tumors. Hormonal agents such as tamoxifen (brand name Nolvadex), toremifene, raloxifene and progesterones have all been used, often in combination with NSAIDs.


Chemotherapy may be effective in patients with unresectable tumors, and is often used if tumors do not respond to tamoxifen and/or sulindac.

New drugs

Desmoid tumors sometimes respond to the tyrosine kinase inhibitor imatinib, brand name Gleevec, an effect that is presumably due to expression of one of Gleevec’s molecular targets, PDGF receptor, on desmoid tumors. Antifibrotic agents seem to represent a rational choice for therapy.

Ongoing clinical trials (latest update Oct. 2012)


The German Interdisciplinary Sarcoma Group (GISG) is currently conducting a phase II trial for
patients suffering from desmoid tumors which cannot be completely resected by surgery with R0 intent or accompanied by unacceptable function loss. Imatinib (Glivec®), a tyrosine kinase inhibitor, is a wellknown therapy against chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST), and there are scientific hints available, that it might be active in treatment of desmoid tumors. The objective of the trial is to show the activity and safety of imatinib in patients with desmoid tumors. In case of progression during imatinib therapy, the trial raises the possibility to continue the treatment with a second-generation tyrosine kinase inhibitor, nilotinib (Tasigna®).

A Pilot Study Evaluation the Use of mTor Inhibitor Sirolimus in Children and Young Adults with Desmoid-Type Fibromatosis (from the University of Chicago, Prof. Skapek)

This study is currently recruiting participants. Last Updated: December 21, 2010

For detailed information click here

Phase II randomized study evaluating Pazopanib versus Methotrexate/Vinblastine in adult patiens with desmoid tumours (DESMOPAZ - Institute Bergonie, Bordeaux, Dr. Italiano)

The purpose of the study is to evaluate the efficacy of Pazopanib in cpmparison to chemptherapy with methotrexate and vinblastine in adult patients with desmoid tunours.

How does the trial work?
Patients who meet the inclusion criteria are eligible for the trial and can start to take 800 mg imatinib daily. For the first 6 month there will be monthly check-ups with blood test, vital signs and side effect checks, after the first 6 month there are 3-monthly check-ups and for the whole study there will be 3-monthly radiological assessments. The trial lasts for 24 months.

For further information please contact Prof. Dr. Peter Hohenberger or Prof. Dr. Bernd Kasper at
Mannheim University Medical Center, phone: +49-621-383-2447 or
German Interdisciplinary Sarcoma Group (GISG), study coordination office, phone: +49-621-383-2447; email: This email address is being protected from spambots. You need JavaScript enabled to view it.

For further reading please visit, SOS-Desmoid, Germany - SOS-Desmoide, Frankreich - Desmoid Tumor Research Foundation - Aggressive FibromatosisDesmoid Tumour Information Page (UK)
The science behind nefopam and desmoid tumors by Dr. Ben Alman (Video)


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