Ewing sarcoma

Ewing sarcoma is a type of malignant (cancerous) tumor that mainly affects children, teens and young adults. These tumors are most often found in bones—particularly the pelvis and longer bones of the arms and legs—but also occasionally develop in soft tissues.

Ewing sarcomas are the second most common cancer starting in bones of patients age 18 or younger, but are still fairly rare. They represent just 1 percent of pediatric cancers, with about 200 children and teens in the U.S. receiving a diagnosis each year. While treatable, Ewing sarcomas are often aggressive, damaging bone and potentially metastasizing (spreading), usually to the lungs or other bones.

The Sarcoma Program at Penn Medicine’s Abramson Cancer Center is home to one of the nation’s most experienced Ewing sarcoma care teams. Our specialists work closely with the sarcoma program at the Children’s Hospital of Philadelphia to bring children the most effective treatment for Ewing sarcoma.

Ewing sarcoma includes several types of related tumors. While there are some differences between them, their cells are similar and their treatments are the same. Together, these tumors are referred to as the Ewing family of tumors and include:

• Ewing sarcoma of bone: This bone sarcoma most commonly develops in the middle of bones but can occur at either end as well. While it’s mainly found in the pelvis and longer bones of the shins, thighs, and upper arms, it can also affect the hips, ribs, and shoulder blades. It’s the most common form of Ewing sarcoma.
• Extraosseous Ewing tumor (EOE): These Ewing tumors form as soft tissue sarcomas, often in the muscles. They’re typically found in the chest, abdomen (belly), arms, or legs. Doctors also call these tumors extraskeletal Ewing sarcomas.
• Primitive neuroectodermal tumor (PNET): These rare tumors form as either bone sarcomas or soft tissue sarcomas. In the chest, they’re called Askin tumors.

Ewing sarcomas may not cause symptoms until the tumor has grown large enough to be seen or felt. These tumors start in the bone but can break into the surrounding muscle and may cause a bump. These bumps typically appear in the pelvis, arms, or legs but may also occur in the chest.

Ewing sarcoma symptoms you may experience include:

• Bone pain at the site of the tumor
• Lump or bump that may feel soft or warm, if the sarcoma has progressed out of the bone
• Broken bones from even moderate injuries
• Fever
• Unexpected weight loss

Researchers don’t fully understand why Ewing sarcoma forms. Understanding these tumors is difficult because they are rare and form in tissues that are still developing as children grow.

Unlike some other bone cancers, we don’t have evidence that Ewing sarcomas run in families or have ties to previous medical treatments. For now, there’s no known way to reduce the risk of developing Ewing sarcoma.

If our team suspects Ewing sarcoma, we will talk with you about symptoms and perform a physical exam focused on any concerning lump, bump, or area of pain.

You may begin with X-rays to allow your care team to see the area of concern and detect any growths that need a closer look. If a tumor is suspected, we will order additional imaging, usually a magnetic resonance imaging (MRI) scan.

In addition to scans, we typically take a small sample of the tumor during an image-guided procedure called a biopsy. Analyzing the sample and using sophisticated molecular tests helps our team confirm a diagnosis and learn more about the cancer.

Together, the exam, imaging, and biopsy help us better understand the Ewing sarcoma. This process, called staging, gives us insight into the tumor’s characteristics and helps us plan the most appropriate and effective treatment.

The outlook for Ewing sarcoma depends on where it forms, its size, and whether it has spread. Treatment also takes age into account as it relates to bone growth. To ensure this comprehensive approach to treatment, it’s best to find a program with a long history of Ewing sarcoma treatment.

People with Ewing sarcoma typically receive chemotherapy as a first treatment. Chemotherapy can help shrink the tumor.

Our doctors then determine whether the tumor should be removed with surgery or treated with radiation therapy. Both treatments can be effective—our team will discuss the potential risks and benefits with you.

If we recommend surgery, the procedure is based on the tumor’s size and location. Our doctors are skilled in the most effective sarcoma surgery method, which removes the entire tumor in one piece. Our surgeons are able to preserve limbs most of the time when tumors are found in arms or legs. We partner with plastic surgeons to ensure an effective surgery that restores appearance and preserves function and potential future growth.

After surgery or radiation, patients will require additional chemotherapy, to reduce the chance that cancer may come back.

Even with the best treatment, Ewing sarcoma can recur (return). To protect your health, we follow you closely after treatment ends. Regular checkups ensure that if cancer does return, we can treat it quickly. We may recommend additional options including surgery, radiation, or drug treatments.

Researchers are developing additional treatment options for Ewing sarcoma, including targeted therapy and immunotherapy. Our program offers clinical trials for sarcoma.