If you or a loved one has been diagnosed with a desmoid tumor, you likely have many questions. Understanding the rarity of these tumors, who they affect, and the challenges they bring can be important for managing your condition. This article explores these topics and offers insights into what they mean for your care.

How Many People Get Desmoid Tumors?

Desmoid tumors form in the body’s connective tissue, which supports and binds other tissues and organs. Each year, about 900 to 1,500 people in the United States are diagnosed with desmoid tumors. The global incidence is estimated to be 2 to 4 people per million annually. While desmoid tumors don’t metastasize (spread to other parts of the body), they can still grow aggressively and cause serious problems.

Who Is Most Likely to Get a Desmoid Tumor?

Anyone can develop a desmoid tumor, but they are most commonly diagnosed in people between the ages of 15 and 60. Females are about twice as likely to develop a desmoid tumor as males, according to the National Organization for Rare Disorders (NORD). This may be due to the influence of the hormone estrogen, which promotes tumor growth and tends to be higher in females than in males, according to research in the Journal of Personalized Medicine.

Desmoid tumors can develop in any part of the body, including the abdominal wall, arms, legs, and chest. Some develop deep inside the abdomen (belly), known as intra-abdominal desmoid tumors. These tumors can grow around vital organs, such as the intestines, complicating treatment.

Desmoid tumors may also develop during or after pregnancy, possibly due to hormonal changes and stretching of the abdominal muscles.

Desmoid Tumors and Familial Adenomatous Polyposis

Most desmoid tumors occur without a known cause or family history. However, some cases are linked to specific causes or risk factors. One is a rare genetic condition called familial adenomatous polyposis (FAP). FAP causes hundreds of polyps (small growths) to develop in the intestines and increases the risk of colon or rectal cancer.

Research findings vary as to the likelihood of developing a desmoid tumor if you have familial adenomatous polyposis (FAP), with estimates ranging from 3.5 percent to 32 percent. These tumors often occur in the abdomen, especially after surgery or injury to that area. If you have FAP or a family history of colon polyps or colon cancer, it’s important to talk to your doctor about your potential risk for desmoid tumors.

Challenges of Living With a Rare Condition

Living with a rare condition like a desmoid tumor comes with unique challenges. These tumors can be difficult to diagnose, and finding effective treatment options can be a challenge because they are so rare.

Getting the Right Diagnosis

Desmoid tumors are not well known, which means that many people experience a long and frustrating journey to get an accurate diagnosis. These tumors can resemble other conditions, including other soft tissue sarcomas (cancerous tumors in the connective tissues), benign (noncancerous) growths, or various cancers. Some individuals may have a lump or swelling that is painless, while others experience discomfort, stiffness, or difficulty moving. This can lead to numerous tests and doctor visits before a proper diagnosis is made.

Finding a Specialist

Because desmoid tumors are rare, it can be challenging to find specialists who are experienced in treating them. You may need to travel to a larger medical center or find a doctor who focuses on rare conditions to receive the best care. Seeking a second opinion from a specialist can be valuable for confirming your diagnosis and exploring all available treatment options.

Choosing a Treatment

Treatment of desmoid tumors can be complex, as there is no single approach that works for everyone. Some tumors grow slowly or may even shrink without treatment. If your tumor is small and not causing symptoms, your doctor might recommend “watchful waiting” — also called “active surveillance” — which means monitoring the tumor closely without immediate treatment.

If the tumor grows or causes symptoms, treatment options might include surgery, medication, or other therapies. Surgery was once the standard treatment, but it is now often reserved for cases where the tumor is small and easily removed, due to the risk of complications or recurrence.

Your care team may suggest medications, such as nirogacestat (Ogsiveo), which is the only drug for desmoid tumors approved by the U.S. Food and Drug Administration (FDA) as of October 2024. Other off-label medications might also be considered. Depending on your needs, treatments such as chemotherapy, targeted therapy, radiation therapy, or cryoablation (a technique that freezes the tumor) may be options to discuss with your doctor.

Navigating the Emotional and Psychological Impact

Living with a rare condition like a desmoid tumor can feel isolating, especially when few people are familiar with it. You may feel uncertain about your condition and the decisions you need to make about your care. Many people experience anxiety, especially around the regular imaging tests used to monitor the tumor’s growth, such as magnetic resonance imaging (MRI) scans. This anxiety, sometimes called “scanxiety,” can make the waiting process for test results particularly stressful.

If you’re feeling overwhelmed or anxious, consider talking to your health care team. They can connect you with a therapist who understands the emotional challenges of living with a rare condition and can help you manage your stress.

Moving Forward With a Desmoid Tumor

If you’ve been diagnosed with a desmoid tumor, remember you’re not alone. Support groups like MyDesmoidTumorTeam and organizations such as the Desmoid Tumor Research Foundation can connect you with others who understand what you’re going through. These groups offer valuable information, a chance to share experiences, and emotional support.

While managing a desmoid tumor can be challenging, ongoing research is leading to new treatments and insights. Staying informed about the latest developments and clinical trials, and working closely with your health care team, can help you feel more empowered in managing your condition.

Talk With Others Who Understand

MyDesmoidTumorTeam is the social network for people with desmoid tumors and their loved ones. On MyDesmoidTumorTeam, members come together to ask questions, give advice, and share their stories with others who understand life with desmoid tumors.

Have you recently been diagnosed with a desmoid tumor? What treatments have you received? Share your experience in the comments below, or start a conversation by posting on your Activities page.