Fibrosarcoma

What is fibrosarcoma?

Fibrosarcoma is a rare soft tissue cancer (sarcoma). If you develop fibrosarcoma, you have a soft tissue tumor in the connective tissues that keep parts of your body together. These tissues include tendons and ligaments. Sometimes, fibrosarcoma forms inside bones or in fibrous connective tissue covering bone.

Fibrosarcoma most often forms in soft tissue deep inside your leg (especially your shin bone or thigh bone), upper arm, knees or trunk. Less often, they start in your head or neck.

If you or your child is diagnosed with fibrosarcoma, what comes next depends on lots of things — from your age to the tumor’s size and location. Your healthcare provider will explain what to expect based on your diagnosis.

Types

There are two types of fibrosarcoma. They’re very different:

• Infantile (congenital) fibrosarcoma. This type usually presents at birth or shortly after. It grows fast but rarely spreads. It’s usually curable.
• Adult-type fibrosarcoma. This type is most common in adults between 20 and 60. But it can also affect older children and adolescents. Unlike the infantile type, adult-type fibrosarcoma is typically more aggressive and harder to treat.

How common is fibrosarcoma?

Fibrosarcoma is rare in both adults and children. The adult type accounts for approximately 10% of soft tissue sarcoma diagnoses. Infantile fibrosarcoma is one of the most common sarcomas diagnosed in children under 5, but it’s still rare overall. It affects fewer than 5 out of 1 million infants.

What are the symptoms of fibrosarcoma?

It usually takes time for fibrosarcoma symptoms to surface. Because fibrosarcoma develops in deep soft tissues, you might not notice any changes in your body until the tumor grows bigger and presses on a nerve or blood vessel.

Typical symptoms of fibrosarcoma include:

• A painless or tender soft lump in your legs, arms or trunk.
• Tingling or “pins and needles” feeling or sharp, aching or burning pain (this might be a sign of a pinched nerve near the tumor).
• Unusual swelling (this might be a sign the tumor is pressing on your blood vessels).

Fibrosarcoma symptoms can resemble symptoms of other, less serious conditions. Only a healthcare provider can determine whether the changes are because of a fibrosarcoma or a more common, benign (noncancerous) condition.

What causes fibrosarcoma?

Researchers haven’t pinpointed what causes fibrosarcoma, but genetic mutations (changes) in cells likely play a role. Many fibrosarcomas have the same changes in their cell DNA. These changes can cause cells to multiply rapidly and form cancerous tumors.

Medical experts have identified a common mutation in infantile fibrosarcoma. About 90% involve issues with the NTRK gene family (there are three NTRK genes). When these genes aren’t working as they should, tumors can form.

Risk factors

Researchers have identified some inherited conditions that might increase your risk of developing fibrosarcoma:

• Familial adenomatous polyposis
• Li-Fraumeni syndrome
• Neurofibromatosis type 1
• Nevoid basal cell carcinoma syndrome
• Retinoblastoma
• Tuberous sclerosis
• Werner syndrome

Other conditions associated with fibrosarcoma include:

• Bone infarction (lack of blood flow causes bone cells to die)
• Chronic (long-term) osteomyelitis
• Fibrous dysplasia
• Paget’s disease of the bone

Risk factors related to your environment and previous medical history include:

• Previous radiation therapy directed toward the area with the tumor
• Previous severe burn at the tumor site
• Exposure to certain chemicals, such as thorium dioxide, vinyl chloride or arsenic
• Exposure to certain metals in orthopedic implants, like chromium, cobalt or nickel

How is fibrosarcoma diagnosed?

Healthcare providers perform several tests when diagnosing fibrosarcoma. They’ll use what they learn to establish a stage and grade for your fibrosarcoma. Tests might include:

• Magnetic resonance imaging (MRI). This is the most common imaging test for diagnosing fibrosarcomas. It can show a tumor’s size and location, and if it impacts blood vessels or nerves.
• Computed tomography scan (CT scan). This test uses a series of X-rays and a computer to create 3D images of your soft tissues and bones.
• Biopsy. A provider may remove tissue from the lump (core needle biopsy), or they may cut it out entirely (excisional biopsy). A pathologist will check the tissue for cancer cells in a lab. 
• Immunohistochemistry (IHC). This lab test uses proteins called antibodies to determine whether a tumor is a fibrosarcoma or a different type of soft tissue tumor.

Stages of fibrosarcoma

Healthcare providers stage fibrosarcoma to determine how advanced it is. Your provider will consider the tumor’s size, location and if it’s spread. They’ll also grade the cancer, which is based on how abnormal the cells look under a microscope. Tumors with abnormal-looking cells are “high” grade and tend to be more aggressive. 

The stages of fibrosarcoma are:

• Stage I: Low-grade fibrosarcomas. More advanced Stage I tumors are bigger than 5 centimeters (cm).
• Stage II: Mid-grade or high-grade fibrosarcomas. More advanced Stage II tumors are bigger than 5 cm.
• Stage III: High-grade fibrosarcomas. Stage III tumors are larger than 5 cm and have spread to nearby lymph nodes.
• Stage IV: Fibrosarcomas of any grade or size that have spread to distant organs or tissue.

Your provider will explain how the cancer stage will impact your prognosis, or likely outcome following treatment.

How is fibrosarcoma treated?

Fibrosarcoma treatment depends on lots of factors, including your overall health, preferences and the tumor type.

For adult-type fibrosarcoma, healthcare providers typically use:

• Surgery. During surgery, providers remove the tumor and a margin of healthy tissue to ensure no cancer cells remain.
• Radiation therapy. You may need radiation therapy before surgery to shrink the tumor or afterward to destroy any remaining cancer cells.
• Chemotherapy. Although some providers prescribe chemotherapy, results are mixed when it comes to this treatment. Chemotherapy doesn’t work on most adult-type fibrosarcomas.

For infantile fibrosarcoma, surgery to remove the tumor is often curative. Your healthcare provider may also recommend:

• Radiation and/or chemotherapy. These treatments can shrink tumors before surgery or destroy any remaining cancer cells after surgery. Unlike the adult type, most infantile-type fibrosarcomas respond well to chemotherapy.
• Targeted therapy. This treatment can stop cells from dividing too fast because of problems with the NTRK genes. It can shrink tumors, making surgery easier. 

How can I reduce my risk of fibrosarcoma?

You can’t prevent fibrosarcoma. But understanding your biological family’s medical history may help with early diagnosis and treatment. Fibrosarcoma appears to be related to some inherited conditions. If your family has a history of one of those conditions, ask your healthcare provider about monitoring your health for signs of this condition.

What can I expect if I have fibrosarcoma?

The outlook for infantile-type fibrosarcomas is excellent. Most are curable with a combination of surgery, radiation chemotherapy or targeted therapy.

The outlook is more complex with adult-type fibrosarcomas. Many tumors aren’t diagnosed until they’ve grown large enough to be noticeable, soft lumps that affect your nerves or circulation. Like many types of cancer, early diagnosis can lead to a better outcome. Fibrosarcoma is much harder to treat once it’s advanced. About half return after treatment. 

Still, many factors affect your prognosis. Some factors, like your age and overall health, are unique to you. Others, like the tumor stage and grade, depend on the fibrosarcoma.

Ask your healthcare provider what factors impact your prognosis.

What is the survival rate for fibrosarcoma?

Between 40% and 60% of people who have adult-type fibrosarcoma are alive five years after diagnosis. Researchers are investigating several new ways to slow fibrosarcoma’s growth.

The 10-year survival rate for infantile-type fibrosarcoma is 90%. That number is closer to 100% if surgery successfully removes all traces of the cancer.

How do I take care of myself if I have fibrosarcoma?

Often, a cancer diagnosis makes people feel powerless. Committing to self-care during and after cancer treatment is one way to manage those feelings. Here are some things you can do:

• Understand your follow-up care plan. Ask your healthcare provider what to expect when it comes to your recovery and follow-up appointments. Knowing what comes next can keep your focus on what you can control rather than what you can’t.
• Address anxiety. Regular checkups and tests after treatment are an important part of catching a recurrence (cancer coming back). But they can cause anxiety, too. Speak to a therapist for help managing anxiety.
• Ask for help. You’ll probably need help while you’re going through treatment. Your loved ones are likely anxious to do what they can. Let them know how they can help you.
• Focus on wellness. Eating nutritious foods, getting adequate physical activity and logging enough hours of sleep each night is just as important with a cancer diagnosis as without.
• Rest. Cancer and cancer treatments can leave you feeling exhausted. Plan to rest as much as possible during your treatment.
• Combat stress. Cancer is stressful. Activities like meditation, relaxation exercises and deep breathing exercises can help ease stress.

When should I see my healthcare provider?

Most people see their providers every three months for the first two years after treatment and then at longer intervals until four or five years after treatment. This timeline helps providers detect any recurrences immediately. When fibrosarcoma comes back, it usually does so within the first five years.

You should always contact your provider any time you notice new lumps or have new pain. While lumps and pain might not be cancer, you should see your provider so they can check your symptoms.

When should I go to the emergency room?

Many cancer treatments affect your immune system, increasing your chance of developing infections. Symptoms that might require an emergency room visit during treatment include:

• Fever of 100.4 degrees Fahrenheit (38.3 degrees Celsius) and above
• Chills
• Productive or “wet” cough
• Stomach pain
• Persistent diarrhea
• Persistent nausea and vomiting

What questions should I ask my healthcare provider?

Questions you might want to ask include:

• How advanced is the fibrosarcoma?
• What treatments do you recommend?
• Will I have a single treatment or more than one kind of treatment?
• What’s the success rate for these treatments?
• What are the side effects of each treatment?