If you or a loved one has been diagnosed with desmoid tumor, you likely have a lot of questions about this rare disease. Understanding more about desmoid tumor can help you know what to expect and what kinds of questions you may want to discuss with your doctor.

To learn more about desmoid tumor, we spoke with Dr. Seth M. Pollack, a professor at Northwestern University Feinberg School of Medicine in the Division of Hematology & Oncology. Dr. Pollack is a medical oncologist and sarcoma specialist and serves as the director of the sarcoma program at Northwestern.

Desmoid tumor — also known as aggressive fibromatosis — is a type of noncancerous tumor that grows in the body’s connective tissue. Desmoid tumor typically occurs in the arms, legs, or abdomen but can form in other areas of the body. The condition is often treated by a specialist in sarcoma because it’s a type of soft tissue tumor that’s related to soft tissue sarcoma, which is a type of cancer.

Here are some desmoid tumor facts Dr. Pollack shared that you can discuss more with your doctor.

1. Most People With Desmoid Tumor Live Normal Lives

Dr. Pollack was quick to point out that the prognosis for many people living with desmoid tumor is good. “For most patients, it doesn’t have to be that big a deal,” he said. In most cases, desmoid tumor is not a life-threatening condition if it’s not growing in parts of the body that affect vital organs.

2. Desmoid Tumor Doesn’t Always Require Treatment

As many as 60 percent of people with desmoid tumors don’t require treatment. In many cases, Dr. Pollack recommends active surveillance of a desmoid tumor without any treatment.

Active surveillance — sometimes called watchful waiting — involves monitoring the tumor through imaging to determine if the tumor is growing or not. Research indicates that 30 percent of desmoid tumors shrink without any treatment.

“For many patients with desmoid tumors, they may have a tumor that is painful or a tumor that’s growing rapidly or in a tough location. And for those patients it might be really important to start treatment immediately,” said Dr. Pollack. Others may have tumors that are “asymptomatic, causing mild symptoms, aren’t growing, [or] are shrinking. You don’t need to treat these patients right away.”

3. Surgery Is No Longer a First-Line Treatment

In the past, surgery was considered the first-line treatment for all desmoid tumors. However, surgery has been found to increase the rate of tumors coming back. Up to 60 percent of desmoid tumors come back after surgery. Surgery also requires removing tissue in a wide margin around the tumor because the small tendrils of a tumor can extend into surrounding tissue. This frequently causes complications after surgery.

It’s important to know that there are still cases where surgery may be the best option. For example, if the tumor is causing blockage in the intestines or causing severe pain or disability, then surgery may be warranted. But in most cases, surgery isn’t needed.

“These days, I’m recommending surgery for very few desmoid tumor patients,” said Dr. Pollack. “A lot of the time I’ve seen that the recurrences happen in a worse way when people have gone to surgery than when they undergo different treatments.”

Dr. Pollack strongly advised people with desmoid tumor to get other medical opinions if a doctor is recommending surgery. Furthermore, he emphasized that people who’ve already had surgery for desmoid tumor should be extremely cautious about having another surgery.

“You really, really do not want to be going for a second surgery after your first surgery,” he said. “The chance that you’re going to have another recurrence after your next surgery is very high.”

4. Surgery May Have Negative Outcomes

When Dr. Pollack started treating desmoid tumors, surgery was still widely used to treat the condition. “We had patients [who’ve] gone for six, seven surgeries. They were debilitating patients who had amputations and all kinds of terrible things,” he recalled.

“People see a tumor, they say, ‘oh, tumors need to be removed.’ But that’s not the case. You can live a very long happy life with just that tumor sitting around doing nothing,” he said. “I think, as a rule, desmoid tumor is a disease where we have to kind of look at it first and do no harm.”

5. Treatment Options Have Expanded for Desmoid Tumor

Fortunately, new treatment options are emerging for desmoid tumor. Just a few years ago there were no drugs approved by the U.S. Food and Drug Administration (FDA) for the treatment of desmoid tumor. Nirogacestat (Ogsiveo), a targeted therapy, was approved by the FDA in 2023. It’s the first FDA-approved therapy for desmoid tumor. Other therapies are used off-label and additional therapies are currently under study and in clinical trials.

Another desmoid tumor treatment option that’s been adopted in recent years is cryoablation. This therapy has been shown to significantly reduce pain, shrink tumors, and increase function in areas affected by tumors.

“Cryoablation is a procedure where there’s a needle that’s stuck into the tumor or maybe multiple needles. And these needles have the potential to get super cold to temperatures where they freeze a radius around the needle and they freeze the entire tumor to kill it,” Dr. Pollack explained.

He went on to say that people who get cryoablation therapy still have a high rate of recurrence, but without the complications and risks of surgery. “These days, if I think that medical therapy isn’t a good option for a patient, the first thing I’m doing is recommending cryoablation, if that’s possible,” Dr. Pollack said.

6. It’s Important To Tell Your Doctor About Worsening Desmoid Tumor Symptoms

It’s important to talk to your care team about any discomfort you may experience with desmoid tumor symptoms. “We always want patients to reach out to us if they have new symptoms, especially pain, because sometimes it means that their tumor’s changing,” said Dr. Pollack.

Sometimes someone may have pain, but new imaging doesn’t show that the tumor has grown. “A very slight change in the tumor could be very painful if the tumor’s up against a nerve,” Dr. Pollack commented. “So even if the tumor is shrinking, it could just grab the nerve tighter.”

A new treatment plan can often help with pain and help improve quality of life. “Sometimes when we start a patient on medical therapy, patients will feel a lot better even before there are visual changes that are in their scan. So even before we can detect shrinkage of the tumor, they just feel a lot better in terms of pain,” Dr. Pollack explained. “Maybe the tumor was grabbing on tightly to the nerve and it just loosened up a little bit.”

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