Welcome! My name is Dr. Mrinal Gounder and I am a sarcoma medical oncologist practicing at Memorial Sloan Kettering Cancer Center in New York City. I am the Scientific Director of DTRF and also a member of the DTRF Medical and Scientific Advisory Board. Over the last decade, I have devoted my efforts to building a clinical practice where I take care of a large number of people diagnosed with desmoid tumors.
Most people have never heard of a desmoid tumor. This is not surprising since every year only about 900 patients (3 in 1 million people!) are diagnosed with this in the United States. Given the rarity of this condition, most doctors have little experience in treating desmoid tumors. I can imagine that you, your child or your loved ones may be feeling anxious, frustrated, confused and/or isolated by this new diagnosis. We are here to help and support you. This is a treatable (and sometimes even curable) condition. I hope that this web page and the larger community that supports DTRF will provide a platform that provides information for you and your physician to make an informed decision together. Another authoritative source for good information is the National Comprehensive Cancer Network (NCCN) guidelines in Soft Tissue Sarcoma.
The good news is that with desmoid tumors there is a tremendous amount of knowledge and cutting edge research that has accelerated during the last decade. As a cancer researcher, I devote a significant amount of my time working with others toward a cure and discovering new drugs to treat desmoid tumors. I am happy to share that in the last few years – thanks in part to the efforts of the DTRF community – the clinicians and researchers working on desmoid tumors have made tremendous progress. We are now seeing an exciting number of new drugs and modalities to treat this condition.
Please remember that desmoid tumors are very complex and the below information is a general overview and 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 seeking professional medical advice regarding your individual circumstances.
What is a desmoid tumor or aggressive fibromatosis?
We think desmoid tumors arise from cells called fibroblasts or myo-fibroblasts. Fibroblast is a type of cell that is found throughout our body from head to toe and is critical to keeping the entire structure of our body intact. They are the structural (scaffold) support for all our vital organs (e.g. lung, liver, blood vessels, heart, kidneys, skin, intestines etc). Without fibroblasts we just cannot survive. Fibroblasts are also involved in wound healing. For example, when we cut ourselves, the fibroblasts start growing and multiplying to heal the wound. Once the wound is healed, normal fibroblasts return to their resting state. We think mutations in the DNA (which make up our genes) cause the fibroblasts to behave abnormally and turn into desmoid tumors.
Desmoid tumors can arise in virtually any part of the body. They can be slow growing or aggressive. They do not metastasize (spread from one body part to another). For many patients, desmoid tumors are not life-threatening. However, when they are aggressive they can cause life- threatening problems or even death when they compress important organs such as intestines, kidneys, lungs, blood vessels, nerves, etc.
Desmoid tumors are rare
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.
Causes of desmoid tumors
The cause of most desmoid tumors is unknown and thus they are called “sporadic” or random. 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, there 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.
Clinical presentation and behavior of desmoid tumors
As mentioned earlier, desmoid tumors can develop at virtually any site in the body. They can have a wide range of clinical symptoms or no symptoms at all. Many desmoid tumors are accidentally picked up on a scan or a routine physical exam done for other medical reasons. Many people have no symptoms at the time of diagnosis or even after many years. Some people feel a range of symptoms that range from slight to severe pain, decrease in their movement or range of motion, swelling of the area affected by the desmoid tumor, loss of sleep, anxiety and many other symptoms. Desmoids deep inside the abdomen or pelvis can also be entirely without symptoms or they can cause bloating, 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.
It is important to know that the desmoid tumors that present superficially on the abdominal wall behave much differently than the ones that are deep inside the abdomen or pelvis. One very interesting aspect of desmoid tumors is that on some occasions they can shrink or become quiescent (deep sleep) without any therapy. Other desmoid tumors may be stable or grow very slowly over a period of months and years. A small subset of desmoid tumors may be aggressive and grow rapidly. In conclusion, these tumors exhibit a wide range of behaviors and therefore their management is very different.
There are many non-invasive methods to evaluate a desmoid tumor which include ultrasound, CT and/or MRI scans. The actual diagnosis of a desmoid tumor can only be made after a small piece of the tumor is examined under the microscope by a trained pathologist. There are no blood tests or non-invasive tests that can make the diagnosis. Depending on the location of the desmoid tumor your physician will recommend the optimal manner to biopsy it. In rare circumstance, a biopsy may not be safe or feasible.
When a biopsy is recommended, there are a variety of options which include: a core needle biopsy which takes a small piece, usually 1 mm wide by 10 mm long; and, surgical biopsies which may take a portion of the tumor (“incisional biopsy”) or may remove the entire visible tumor (“excisional biopsy”). While an excisional biopsy may remove all visible tumor, when pursuing this option it is necessary to discuss with your surgeon the possibility of leaving some tumor behind – either gross or microscopic – and most importantly, what are the short-term and long-term side effects of the excisional biopsy. The pathologist takes very fine sections of the biopsy material and examines them under the microscope looking for special features that define desmoid tumors.
If you are diagnosed with a desmoid tumor it is recommended that (if possible for you and allowed by your insurance) you be evaluated in a hospital with experts in sarcoma. These hospitals are usually designated as NCCN (National Comprehensive Cancer Network) centers but not all NCCN centers have expertise in sarcoma. Before making an appointment it is good to know whether they have experts in sarcoma. Ideally, patients with desmoid tumors should be evaluated by a multi-disciplinary team which includes surgeons, medical oncologists, radiation oncologists, geneticists and nurses.
- Observation or “waiting and watching.” Desmoid tumors display a wide range of behaviors. This can range from shrinking spontaneously without any intervention, to remaining stable or growing rapidly. In some circumstances, it is reasonable to just watch the tumor carefully with images and/or physical examination. How often you need scans and/or physical exams during a “wait and watch” period will vary for each situation and your treating physician will discuss this with you.
- Surgery. Historically, most people with desmoid tumors underwent some form of surgery. Over the last few decades, it is increasingly being recognized that these tumors have a high risk of returning even with surgery. While statistics may vary, about 25 to 40 percent of patients who undergo surgery can have a local recurrence (return at or near the original site). The goal of surgery is to remove the entire tumor and minimize the risk of recurrence. Scientific research has shown that some types of desmoid have much higher risk of recurrence after surgery than others. This can be calculated using an online calculator (MSKCC nomogram). All nomograms are estimations and not always accurate. When making a decision to undergo surgery, you have to have an open conversation with your surgeon about the risk of recurrence, time to recurrence and the short-term and long-term side-effects of the surgery. Increasingly, surgery is falling out of favor for desmoid tumors given their high risk of recurrence and other side effects. In some circumstances, surgery may be the best option and can result in great outcomes including a cure. In conclusion, the decision to undergo surgery is a complex one and should be weighted carefully.
- Radiation Therapy. Radiation therapy may be an effective option for a few patients in special circumstances. The dose and duration of radiation is highly variable and your radiation oncologist will discuss that with you. Both the short-term and long-term side effects from radiation should be carefully considered. In general, many sarcoma experts do NOT recommend radiation out of the concern for developing a new (aggressive) cancer due to the radiation. In conclusion, the decision to undergo radiation is a complex one and needs to be discussed carefully.
- Thermal ablation does not use radiation but rather heat or cold to kill the desmoid tumor. This is an emerging technique where needles are inserted into the tumor and thermal waves are used to heat or freeze the tumor. High-frequency ultrasound is another technique which uses ultrasound waves to destroy the tumor. These techniques are only suitable for certain types of desmoid tumors. Overall, this is a relatively new technique and the experience to date is limited to a few centers, and the long-term results are not yet known. In conclusion, the decision to undergo ablation (hot, cold or ultrasound) is a very technical and complex one and needs to be discussed carefully with the interventional radiologist. Only a few highly specialized centers have expertise in treating desmoid tumors using these techniques.
- Medical Therapy. There is no single accepted medical treatment for desmoid tumors. Based on your medical health and nature of your desmoid tumor, your medical oncologist will discuss with you the best options for you. 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 (liposomal doxorubicin), 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 has not been fully investigated in clinical trials. A new class of agents called tyrosine kinase inhibitors (e.g. sorafenib) has shown benefit in desmoid tumors by shrinking the tumors or slowing down the growth. These are pills taken by mouth at home.
While a great amount of progress has been made in our understanding of desmoid tumors, there is still a long road ahead. While many therapies are available to treat desmoid tumors, there are often very promising new modalities that are being evaluated in clinical trials. The NCCN recommendation for all patients is to participate in clinical trials whenever possible.
Mrinal Gounder, M.D. Melanoma and Sarcoma Service, Memorial Sloan-Kettering Cancer Center Scientific Director, The Desmoid Tumor Research Foundation