Frequently Asked Questions
Explore some frequently asked questions from our community for quick answers and links to more detailed information. Remember to always consult with your healthcare provider if you have any questions or concerns about the diagnosis or management of your desmoid tumor.
Diagnosis
Symptoms from desmoid tumors vary greatly depending on the tumor location but can include pain, swelling, visible deformities, impact on mobility, and pressure on nearby organs affecting bodily functions such as urinary or bowel function, breathing, or swallowing. By contrast, some patients may have no symptoms at all and no visible physical manifestation of the tumor.
Learn more about diagnosis and the causes of desmoid tumors.
You will find that the medical community, articles and other sources will use differing terms when describing desmoid tumors. This can be confusing to patients as well as clinicians, and can lead to misunderstandings about treatment and minimize consideration of the potential serious consequences of the disease.
First, what is a “tumor?” A tumor is a non-specific term that simply means “a growth.” The word “tumor” does not imply anything about whether the growth is cancerous or non-cancerous.
Patients often ask, “Are desmoid tumors cancer?” The classifications set out by the World Health Organization (the “WHO”) for soft tissue tumors are the most decisive and descriptive on this question.3 The WHO classifies soft tissue tumors in the following four categories:
- malignant,
- intermediate (sometimes metastasizing),
- intermediate (locally aggressive) [desmoid tumors],
- benign.
Malignant tumors spread to distant sites via the bloodstream or the lymphatic system. This spread is called metastasis. Desmoid tumors do not metastasize. For this reason, some sources will inaccurately use the simple term “benign” when referring to desmoid tumors, presumably because “benign” is a common medical term for a tumor that does not metastasize. However, the term benign does not take into account that desmoid tumors can cause destruction, functional problems, or pain in the area where they are growing. This is why the WHO categorizes desmoid tumors as “locally aggressive,” and the WHO guidelines go on to explain: “It is now broadly accepted that in between benign and malignant categories there exists an ‘intermediate’ category of lesions that can be locally aggressive,” and desmoid fibromatosis is classified in that intermediate category.3
It is important to note that desmoid tumors do not always behave aggressively. Some never cause symptoms, problems, or need to be treated.
The doctors that specialize in desmoid tumors are sarcoma specialists, which is a group of oncologists with expertise in treating sarcomas. Sarcomas are rare types of cancers that form in the connective tissues in the body (for example, muscle, fat, blood vessels, bone, and cartilage). Because desmoid tumors also arise in connective tissues, they are within the purview of sarcoma specialists. Sarcoma specialists may consider treatments for desmoid tumors that are also used in sarcomas or other cancers (for example, chemotherapies, targeted therapies, local ablative or embolization techniques, and radiation therapy). As such, desmoid tumors may be referred to as “cancers” in some clinic documentation or insurance records so that the proper treatment is recognized and covered by insurance.
Patients are strongly encouraged to seek consultation and treatment from sarcoma specialists because they are most likely to be familiar with this rare disease and its recommended treatments.
To make a definitive diagnosis, your oncologist will perform a biopsy to collect a sample of the tumor tissues and a pathologist will examine the tumor cells in a lab. Overproduction of a protein in the cells called beta-catenin[Link to this entry in Glossary] can be used as an indicator to help doctors diagnose desmoid tumors. Your doctor can also perform a physical exam to better understand your described symptoms.
In most cases, magnetic resonance imaging (MRI) is the imaging test of choice to monitor and measure a desmoid tumor. MRIs have superior soft tissue contrast compared to computed tomography (CT) scans; in other words, desmoid tumors are easier to see on an MRI against a background of other soft tissues such as muscle. In addition, MRIs are more accurate at assessing the degree of cellularity (the quantity of active tumor cells shown via T2 signal when compared to CT scans, which is beneficial for determining treatment response. Additionally, unlike X-rays and CT scans, MRIs do not emit ionizing radiation.
CT is usually the modality of choice for imaging mesenteric desmoid tumors because bowel motion can make it difficult to see these tumors on MRI. However, once the location of the desmoid tumor is identified with a baseline CT, MRI can be used for follow-up imaging in order to eliminate the radiation exposure one receives from repeated CT scans.
Fibroblasts are a type of cell found throughout our bodies in connective and soft tissues. They are the structural support for our vital organs (e.g., lung, liver, blood vessels, heart, kidneys, skin, intestines, etc.) and are also involved in wound healing. A desmoid tumor forms when fibroblasts or “myofibroblasts” multiply excessively. This is caused by a spontaneous mutation in the CTNNB1 gene that causes overexpression of the protein beta-catenin in the cells. Desmoid tumors can also occur as a result of a genetic mutation in the adenomatous polyposis coli (APC) gene, which also causes an inherited disease called familial adenomatous polyposis (F.A.P.) – a cancer predisposition syndrome.2
Through medical imaging, desmoid tumors appear as a solid mass in the body’s connective tissues. Patients may see what looks like an area of swelling on their body. Due to the different diagnoses that can accompany tumors, it is advisable to visit a specialist when you notice any mass in the body. While certain characteristics are identifiable in imaging, only a biopsy can definitively confirm whether or not a person has a desmoid tumor.
Desmoid tumors are distinctly rare, with an incidence of 5–6 cases per one million of the population per annum. The peak patient age is 30–40 years. However, desmoid tumors can occur in anybody of any age.2 They are also found more commonly in females compared to males (2:1).6
Because of how rare desmoid tumors are, it is critically important to seek out a doctor who is familiar with this disease — typically a sarcoma specialist. Sarcoma specialists can be found at sarcoma centers within or connected to major academic medical centers and can help support you with a multidisciplinary medical team. These major medical centers may have designations as a National Comprehensive Cancer Network (NCCN) or as a Sarcoma Alliance for Research through Collaboration (SARC) center.
There are a variety of treatments that are used to treat these tumors, but their effectiveness can vary from patient to patient. Please refer to the Global Consensus Paper [link to ‘Global Consensus Paper’ page] for a description of treatments and recommendations. Because of these unpredictable behaviors, active surveillance (close monitoring and imaging of the tumor over time) is the recommended primary approach to desmoid tumors. However, this will vary depending on the tumor location. Surgery is no longer recommended as a first-line treatment. It may be considered as a second-line treatment specifically for sporadic abdominal wall desmoid tumors. If surgery is being considered, it is strongly recommended that it be performed by a surgeon with significant experience in desmoid tumors.3 Before making a decision to undergo surgery, you should have an open conversation with your surgeon and medical oncologist about the risk of recurrence, time to recurrence, and the short-term and long-term side-effects of the surgery. Chemotherapy, targeted therapy, or ablations may be recommended to help shrink or remove the tumor. However, these tumors are often recurring, even after treatment.
Yes, most desmoid tumor cases are non-life threatening. Certain factors can influence each person’s individual quality of life and health, such as the tumor size, location, rate of growth, and any potential side effects from the tumor or tumor treatments. Even if you are not experiencing symptoms, it is important to be monitored by a sarcoma specialist familiar with desmoid tumors. Also, taking care of your mental health and connecting with the desmoid tumor patient and caregiver community can help support your overall quality of life while living with this disease.
Desmoid tumors can become life-threatening when they compress or involve vital organs such as intestines, kidneys, lungs, blood vessels, nerves, etc., which is why it’s important to see a sarcoma expert experienced in desmoid tumors to better understand your particular situation.6
While most desmoid tumors are not life-threatening, they can still be locally aggressive and can severely damage surrounding tissues and vital structures as they grow. This can cause pain and impair mobility and function. Proper monitoring of these tumors by a sarcoma specialist is important as symptoms and tumor growth rates can change over time.
Pregnancy
Every situation is different and patients should discuss their pregnancy decisions with a sarcoma specialist. Recent research has concluded that most desmoid tumor patients should not be counseled to avoid getting pregnant, or against carrying subsequent pregnancies after an initial desmoid tumor. However, tumor location, tumor growth rate, symptoms, recent treatment, and other factors should be considered in conversations with your specialist. It is important to be closely monitored during pregnancy by your care team since the rate of growth of the desmoid tumor may change during pregnancy. If you are considering becoming pregnant, please be sure to speak with your care team.
Consultations and Treatments
It is important for desmoid tumor patients to find a sarcoma specialist to manage their care. The way in which desmoid tumors are managed depends greatly on the individual case and factors like location, size, rate of growth, and symptoms. However, the Global Consensus Paper on Desmoid Tumor Treatment recommends that clinicians initially monitor the tumor over a period of time to see if the tumor is shrinking, stable, or growing. This is called “active surveillance” or “waiting and watching.” If it is determined that you need a medical intervention for your desmoid tumor, your doctor will begin discussing potential treatment options with you. Research has shown that up to 30% of desmoid tumors may regress on their own. Due to the chance of regression and the high rate of recurrence, surgery is no longer recommended as a front-line treatment for desmoid tumors. Surgery may be a second-line treatment only for abdominal wall desmoid tumors as studies have shown that the recurrence rate is lower for that tumor location.2
Active surveillance will include imaging. To monitor and measure a desmoid tumor over time, magnetic resonance imaging (MRI) is the best choice in most cases. This is because of its superiority over computed tomography (CT) scans in soft tissue contrast and assessing the degree of cellularity (quantity of active cells), without emitting ionizing radiation. The exception where MRIs are not preferred is when a desmoid tumor is in the bowel, due to the constant movement of the bowel. In that case, CT scans or ultrasounds are the preferred imaging test.2
Desmoid tumor behavior can vary and treatment heavily depends on your tumor location and symptoms. If you and your clinician determine your tumor should be treated, there are multiple options. These include, but are not limited to, medical treatments such as chemotherapy, targeted therapies, and ablation therapies. Due to the chance of regression (20-30%)2 and the high rate of recurrence (25-60%),7 surgery is no longer recommended as a first-line treatment for desmoid tumors. However, surgery may be a second-line treatment for abdominal desmoid tumors as the recurrence rate is lower for that tumor location. Your desmoid tumor treatment may also depend on whether or not you also have the genetic condition familial adenomatous polyposis (F.A.P.).2
The Global Consensus Paper on Desmoid Tumor Treatment is an international evidence-based consensus on the treatment of desmoid tumors. It answers critical questions regarding approach to treatment recommendations, types of treatments, and pain management. For more information about desmoid tumor treatment guidelines, visit the Global Consensus Paper page.
Medical therapies to treat desmoid tumors may vary. What works for one patient may not necessarily work for another, but progress is being made through research. Visit the Treatment and Monitoring page to learn about the variety of therapies often used in the treatment of desmoid tumors.
It is important to seek out a sarcoma specialist, as they are more likely to be knowledgeable or familiar with desmoid tumor care. Sarcoma specialists can typically be found at major sarcoma centers within or affiliated with academic medical centers and can help support patient care through a multidisciplinary medical team. These major medical centers may have designations as a National Comprehensive Cancer Network (NCCN) or as a Sarcoma Alliance for Research through Collaboration (SARC) center.
Surgery was previously the primary treatment for desmoid tumors, but the risk of local recurrence remains between 25-60% for patients.7 Due to this high rate of recurrence, surgery is no longer recommended as a first-line treatment for desmoid tumors. Desmoid tumors often have infiltrating tumor borders, which can appear as thin tendrils that reach into nearby tissues. This can make it difficult for surgeons to obtain negative margins, causing an increase in the surgical area or the likelihood of recurrence. Desmoid tumors can still recur even in the presence of negative margins.
Learn more about treatment and monitoring
Dr. Aimee Crago of Memorial Sloan Kettering Cancer Center created a nomogram which can be used to help predict the risk of recurrence following surgical resection of a desmoid tumor. Please read the disclaimer on the Memorial Sloan Kettering nomogram page and discuss the results with your clinician for further context and understanding.
There are no special diets proven to decrease or eliminate a tumor. However, it is always recommended to follow a balanced diet and maintain a healthy lifestyle.
You may also be advised by your doctor or nutritionist to follow a specific diet or avoid certain foods if you are on chemotherapy or undergoing treatment for your desmoid tumor. We recommend speaking with your doctor about any specific diet concerns or considerations, including before taking any supplements or vitamins as they can sometimes interfere with treatment or each other. Some offices or hospitals will offer consultations with a nutritionist to support you through your treatment.
Taking care of your mental health throughout your desmoid tumor journey is essential. Explore our list of mental health resources to help support you. Connecting with others within the desmoid tumor community can also be beneficial for patients and their families. Remember: you are not alone.
If you are in crisis, call the U.S. National Suicide & Crisis Lifeline by dialing 988. For international hotlines, go here.
Read Patient & Caregiver Stories
Learn about the annual DTRF Together We Will Weekend each September where patients can gather and connect with each other.
To connect to helpful DTRF resources and those from other organizations, explore our list of resources for patients, caregivers and families organized by category.
For more information about treatment and monitoring, visit our Treatment and Monitoring page.
For more information about mental health resources, visit our Mental Health Resources page .
Imaging
To make a definitive diagnosis, your oncologist will perform a biopsy to collect a sample of the tumor tissue and a pathologist will examine the tumor cells in a lab. Overproduction of a protein in the cells called beta-catenin can be used as a confirmatory indicator to help diagnose desmoid tumors. Your doctor can also perform a physical exam to better understand your described symptoms.
In most cases, magnetic resonance imaging (MRI) is the imaging test of choice to monitor and measure a desmoid tumor. MRI has superior soft tissue contrast compared to computed tomography (CT) scans; in other words, desmoid tumors are easier to see on an MRI against a background of other soft tissues such as muscle. In addition, an MRI is more accurate at assessing the degree of cellularity (the quantity of active cells shown via T2 signal) when compared to CT scans, which is beneficial for determining treatment response. Additionally, unlike X-rays and CT scans, an MRI does not emit ionizing radiation.
CT is usually the modality of choice for imaging mesenteric desmoid tumors because bowel motion can make it difficult to see these tumors on MRI. However, once the location of the desmoid tumor is identified with a baseline CT, MRI can be used for follow-up imaging in order to eliminate the radiation exposure one receives from repeated CT scans.
Genetics
The majority of desmoid tumors occur spontaneously or randomly, meaning there is no clear cause or pre-existing condition related to the desmoid tumor. These “spontaneous” desmoid tumors often have a mutation in the beta-catenin (CTNNB1) gene. A mutation is a change in the DNA or “blueprint” of the gene. Importantly, in these cases, the mutant beta-catenin gene is only found in the desmoid tumor and is not present in the other cells of the body, is not inheritable, and cannot be passed to children.
On the other hand, approximately 5-10% of all desmoid tumor cases are related to a rare genetic condition known as familial adenomatous polyposis (F.A.P.), which is an inheritable condition that can run in families or be passed to children. F.A.P. is caused by a mutation in the APC gene that is present throughout all of the cells of the body.2 Individuals with F.A.P. have a higher risk of colon cancer than the general population, and may have inherited the APC gene, or could pass it along to children. The only way to know for sure if the desmoid tumor is related to F.A.P. is to have genetic testing through a blood test or cheek swab.
The vast majority of desmoid tumors are attributed to a mutation in the CTNNB1 gene. These tumors are considered sporadic and cannot be inherited. Desmoid tumor cases can also occur in the context of the genetic condition familial adenomatous polyposis (F.A.P.), which can be passed down within families. It is important to note that not all F.A.P. patients get desmoid tumors.2
Desmoid tumors are not metastatic, which means they cannot spread through the blood from one body part to another. However, it is important to note that desmoid tumors can spread locally, within the same body part, and have a high rate of local recurrence. Desmoid tumors can infiltrate adjacent tissues and structures as they grow. In rare cases, desmoid tumors may be multifocal, arising in multiples within the same body part or in multiple parts of the body.
Clinical Trials
Yes. Clinical trials for and including desmoid tumor patients are available. Please visit our Clinical Trials page to learn more and view resources to help you decide with your doctor if a clinical trial is right for you.
A clinical trial is a research study that explores whether a medical strategy, investigational medicine, or device is safe and effective for humans.
Regulatory agencies – for example, the U.S. Food & Drug Administration (FDA) or the European Medicines Agency (EMA) – determine whether the treatment can be prescribed by physicians to patients. Before a decision is made, all potential new treatments go through a set of clinical trial phases under controlled conditions. There are 3 phases of clinical research required for a drug to be FDA-approved in a disease and a fourth post-approval phase:
- Phase 1 tests safety in humans by giving the treatment or drug to either patients (with rare diseases) or to healthy volunteers (larger disease populations).
- Phase 2 tests safety and effectiveness in patients living with the disease being studied.
- Phase 3 tests safety and confirms effectiveness in patients with the disease and studies a larger group of people than the Phase 2 trial.
- After a drug is approved, a Phase 4 may be conducted to test the drug’s effect in various populations and any side effects associated with long-term use.
People choose whether or not to participate in clinical trials for various reasons, including:
- Gaining early access to investigational medication
- Contributing to medical research
- Potentially helping future generations of individuals diagnosed with desmoid tumors
Talk to your doctor if you are interested in participating in a clinical trial.
Informed consent is the process where the patient/caregiver/legal guardian is provided clear, easy-to-understand information as they are deciding whether to participate in a clinical trial.
The Institutional Review Board (IRB), International Ethics Committee (IEC), and the regulatory agency ensure that each clinical trial participant receives and understands the informed consent in order to make the most informed decision.
For more information about clinical trials, visit our Clinical Trials page.
COVID-19
Medical care for many individuals has been impacted by COVID-19, and it is important to discuss with your doctor how your treatment and monitoring for your desmoid tumor may be affected. It is also important to keep in mind that some treatments, such as chemotherapy, may cause you to be immunocompromised, making you more at-risk for COVID-19 symptoms and health effects. We recommend speaking with your doctor about how COVID-19 may affect you and your medical care. For vaccine information and more, visit our COVID-19 resources.
For more information about desmoid tumor treatment guidelines, visit the Global Consensus Paper page.
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References
- Master SR, Mangla A, Puckett Y, et al. Desmoid Tumor. [Updated 2022 Nov 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459231/.
- Alman B, Attia S, Baumgarten C, et al. The management of desmoid tumours: A joint global consensus-based guideline approach for adult and paediatric patients. European Journal of Cancer. 2020. 127: 96-107. Accessed April 5, 2023. https://www.sciencedirect.com/science/article/pii/S0959804919308329.
- Marta Sbaraglia, Elena Bellan, and Angelo P. Dei Tos, Pathologica 20221, “The 2020 WHO Classification of Soft Tissue Tumours: news and perspectives,” page 71 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8167394.
- Constantinidou A, Scurr M, Judson I, Litchman C. Clinical presentation of desmoid tumors. In: Litchman C, ed. Desmoid Tumors. Springer; 2012:chap 2. Accessed March 29, 2023. https://www.researchgate.net/publication/226455135.
- Gounder MM, Maddux L, Paty J, Atkinson TM. Prospective development of a patient-reported outcomes instrument for desmoid tumors or aggressive fibromatosis. Cancer. 2020;126(3):531-539.
- Cancer.Net. Desmoid tumor: statistics. Accessed April 21, 2023. https://www.cancer.net/cancer-types/desmoid-tumor/statistics.
- Skubitz KM. Biology and treatment of aggressive fibromatosis or desmoid tumor. Mayo Clin Proc. 2017;92(6):947-964.
- Penel N; Chibon F; Salas S. Adult desmoid tumors: biology, management and ongoing trials. Current Opinion in Oncology 29(4):p 268-274, July 2017. | DOI: 10.1097/CCO.0000000000000374.
- Cleveland Clinic. Familial Adenomatous Polyposis (FAP). Accessed on Apr. 24, 2023. https://my.clevelandclinic.org/health/diseases/16993-familial-adenomatous-polyposis-fap
