Fibrosarcoma

A fibrosarcoma is a cancerous tumor that can be found rarely in soft tissues and even more rarely in bone. As scientists have gained more understanding about soft tissue sarcomas, most tumors previously called fibrosarcoma have been recategorized under different names. What we now know as fibrosarcoma can occur in any of the connective tissues in the arms, legs, trunk, and pelvis.

Fibrosarcomas are very rare, representing just 3 percent of the 13,000 soft tissue sarcomas diagnosed in the U.S. each year. In adults, these tumors mainly affect people who are middle-aged or older. These cancers can act aggressively and metastasize (spread), mainly to the lungs and bones.

The Sarcoma Program at Penn Medicine’s Abramson Cancer Center is highly experienced in treating adults with fibrosarcoma. Our surgeons can often save arms and legs affected by tumors, as well as effectively operate elsewhere in the body. We also know when to consider additional therapy, with a full range of treatment options.

At first, a fibrosarcoma may not cause any symptoms. As it grows, you may experience swelling.

It is currently unknown why most fibrosarcomas form. Several factors, however, can increase the risk of developing one of these tumors:

• Family genetics: Genetic changes inherited from parents sometimes cause syndromes that raise the risk for a range of health conditions. Fibrosarcoma risk is elevated in people with hereditary retinoblastoma and Li–Fraumeni syndrome (LFS).
• Other cancers: In unusual cases, another sarcoma called dermatofibrosarcoma protuberans (DFSP) can have areas of higher-grade fibrosarcoma within the tumor.
• Radiation therapy: An uncommon side effect of radiation therapy is the development of a fibrosarcoma years later.

Fibrosarcomas don’t typically cause symptoms in their early stages, so diagnosis often comes once a tumor grows larger or becomes more advanced. To accurately diagnose a fibrosarcoma, doctors must distinguish it from a growth called a desmoid tumor. They must also rule out similar cancers, including other sarcomas such as:

• Dermatofibrosarcoma protuberans
• Fibromyxoid sarcoma
• Malignant peripheral nerve sheath tumors (specifically, schwannomas)
• Osteosarcoma
• Sclerosing epithelioid fibrosarcoma
• Synovial sarcoma
• Undifferentiated pleomorphic sarcoma

Our specialists start evaluation of a possible fibrosarcoma with an exam of the affected body area.

Imaging scans such as magnetic resonance imaging (MRI) or computed tomography (CT) can then provide information about the tumor’s size, shape, and precise location. To confirm a diagnosis of fibrosarcoma, an image-guided needle biopsy will be performed. We take the resulting tumor sample and send it to our specialized pathologists to study it under a microscope and run lab tests on it. This process helps us determine the cancer’s grade.

Together, the physical exam, imaging, and biopsy results help our team stage the fibrosarcoma. Staging is a more detailed description of a tumor that helps us plan the most effective treatment for you.

Fibrosarcoma treatment at Penn focuses on sarcoma surgery to remove the entire tumor with additional surrounding normal tissue to achieve an adequate margin. Factors that affect prognosis include:

• Age and overall health
• Grade of the cancer
• Tumor location

To reduce the chance that cancer returns, our team may recommend that you receive radiation therapy before the operation, especially for higher-grade tumors.

For cancer that can’t be removed with surgery, or tumors that return or spread, we may recommend chemotherapy. Researchers are also working on other options in sarcoma clinical trials. For example, targeted therapy may stop pathways the tumors use to grow or lower their resistance to chemotherapy.

At Penn Medicine, we offer the latest approaches for fibrosarcoma, including limb-sparing surgery and newer drug therapies.