Diagnosis and Treatment - Desmoid Tumor Research Foundation

Diagnosis and Treatment

Desmoid tumors are tumors that arise from cells called fibroblasts. Fibroblasts are found throughout our body and their main function is to provide structural support and protection to the vital organs such as lung, liver, blood vessels, heart, kidneys, skin, intestines etc. and they also play a critical role in wound healing. When fibroblast cells undergo mutations they can become cancerous and become desmoid tumors (also known as “aggressive fibromatosis”). Desmoid tumors can arise in virtually any part of the body. These tumors often occur in women in their 30’s, but can occur in anyone at any age. Desmoid tumors can be slow growing or extremely aggressive. They do not metastasize (move from one body part to another), and if slow growing they can be carefully watched by your physician. However, when they are aggressive they can cause life threatening problems or even death when they compress vital organs such as intestines, kidney, lungs, blood vessels, nerves etc.

In the United States, approximately 900 people are diagnosed with desmoid tumors every year. This means that out of a million people approximately 2 – 4 people are diagnosed with desmoid tumors each year. Experts believe that the numbers are likely to be far greater because of the difficulty in correctly diagnosing this disease. Because of inconsistent and inaccurate reporting procedures, accurate statistics about the number of desmoid tumor cases have not been kept. Individuals between the ages of 15 and 60 are most often affected, but this disease can occur in anyone. The average age is 30’s to 40’s. They are slightly more common in women than in men (2:1), and there is no significant racial or ethnic distribution.

Listen to Ohio State’s Dr. Pollock discussing desmoid tumors here.

The cause of most desmoid tumors is unknown and thus they are called “sporadic”. Most desmoids have mutations in a gene called beta catenin.

A minority of desmoid tumors are caused by mutations in a gene called Familial Adenomatous Polyposis or FAP. Patients with mutations in the FAP gene are predisposed to forming hundreds of polyps in the intestines and go on to develop colon cancers. Patients with FAP are often recommended to undergo surgical removal of their intestines. These patients are at a very high risk of developing desmoid tumors which can arise deep in the abdomen or in the abdominal wall. In older scientific literature, the combination of FAP and desmoid tumors is termed Gardner’s Syndrome.

In some rare cases, desmoid tumors can occur in women who are pregnant. This happens during pregnancy or after a surgical delivery. Many believe that this is caused by a combination of elevated hormones and surgery, however, these is no strong scientific evidence to support this claim. The relationship between pregnancy and desmoid tumors is very rare and consists of mostly anecdotes in the scientific literature.

Desmoid tumors can develop at virtually any site in the body.  Superficial desmoids tend to be less aggressive than desmoids found deep inside the body (i.e., abdominal, extra-abdominal, mesenteric). Superficial desmoid tumors usually manifest themselves as a painless or slightly painful lump.  Desmoids inside the abdomen can cause severe pain, rupture of intestines, compression of the kidneys or ureters or rectal bleeding. They can compress critical blood vessels such as the mesenteric vessels and the vena cava. Desmoid tumors may have multiple sites of origin on chest, arms or legs.

A biopsy 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.

Read more about MR Imaging of desmoid tumors here.

Although desmoid tumors do not metastasize, the disease may be devastating and occasionally fatal.  Desmoid tumors cause major problems when they become locally aggressive, infiltrating and sometimes causing destruction of adjacent organs (intestines, lungs, blood vessels etc).  Some desmoids can be indolent and have periods of stability and temporary regression. These need to be watched closely by physicians.

If you are diagnosed with a desmoid tumor it is recommended that you be evaluated in a major, academic hospital with experts in sarcoma.  These hospitals are usually designated as NCCN (National Comprehensive Cancer Network) centers.  Patients with desmoid tumors should be evaluated by a multi-disciplinary team of surgeons, medical oncologists, radiation oncologists, geneticists and nurses.  There is no cure for desmoid tumors and when possible patients are encouraged to enlist in clinical trials.

Review the NCCN’s guidelines on making treatment decisions here.

When feasible, desmoid tumors are surgically removed.  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. The goal of surgery is to remove all the tumor and minimize the risk of recurrence.  A recent nomogram (analysis of risk factors) was published that gives a score on the risk of the desmoid recurring even before the surgery is performed.  If the score is high, then the risk of desmoid tumor recurring is high and surgery may not be the best option.  However, if the nomogram score is low then the risk of desmoid recurring is low and surgery may be a good option.  The goal is to attempt to obtain tumor-free margins while preserving function and cosmesis. Surgery may be difficult and even impossible for desmoids within the abdomen. Medical therapy (see below) may be considered as an initial alternative, particularly for tumors that involve the intestines, blood vessels, nerves, or organs. The decision to operate is a complicated process that needs to be carefully discussed in a multidisciplinary team of surgeons and doctors at a major sarcoma center.

Radiation therapy 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. Radiation therapy 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.  In some cases, radiation itself can result in other fatal cancers.  Therefore, the decision to undergo radiation is a complex one and needs to be discussed carefully.

Radiofrequency ablation is an emerging technique where needles are inserted into tumors and radiofrequency waves conducted through the needles lead to intense heating of the tumor. This has also led to some desmoid tumor shrinkage, but the experience to date is limited to a few centers and the long-term results are not yet known.

Dr. Joseph Erinjeri from Memorial Sloan Kettering adds, “Image guided thermal ablation is a novel treatment option for patients with desmoid tumors. Thermal ablation kills the tumor in place, without the need for an incision, unlike surgery (which removes the tumor) or chemotherapy (which poisons the tumor). Specialized needles which cool or heat the tumor are inserted into the tumor under CT or MR guidance. Following the ablation, the desmoid is killed, along with a margin of surrounding tissue. Patients stay in the hospital overnight, and usually resume normal activities within a few days. Most patients require 2-4 yearly treatments to control the tumor. Thermal ablation is typical used as a 2nd or 3rd line treatment for desmoid tumors, but we hope that with further research, thermal ablation can be used as a 1st line treatment in carefully selected desmoid patients.”

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.  Chemotherapy is a chemical drug that is usually injected in the veins.  A few chemotherapies that are commonly used include: doxorubicin, Doxil, dacarbazine, methotrexate, vinorelbine and vinblastine.  These are toxic chemotherapies that can have a wide range of short and long term side effects.  There have also been anecdotal reports of using sulindac (non-steroidal anti-inflammatory) or anti-hormonal agents such as tamoxifen, however the true efficacy of these drugs have not been investigated in clinical trials.

There are a few sarcoma centers in the country that are dedicated to understanding desmoid tumors and coming up with a cure.  A new class of agents called tyrosine kinase inhibitors (such as Gleevec) have shown to be of benefit in some desmoid tumors.  Recently there was remarkable activity noted in sorafenib (Nexavar) and a clinical trial is currently under planning.  The benefit of these newer agents are that they are oral pills and are more tolerable than cytotoxic chemotherapies.

This information has been provided by:

Mrinal Gounder, M.D.
Melanoma and Sarcoma Service,
Memorial Sloan-Kettering Cancer Center
Scientific Director, The Desmoid Tumor Research Foundation

Please note that this summary is intended solely to provide general information for your reference only. This is a very generic document and individual cases will vary considerably. This information is not intended as medical advice for any individual problem, or as a diagnosis, treatment plan, or recommendation for a particular course of action, and should not be used as a substitute for professional medical advice and services. Please do not delay in obtaining professional medical advice regarding your individual circumstances.