Ewing Sarcoma

January 22, 2026

This page was reviewed under our medical and editorial policy by Lee Cranmer, M.D., Ph.D., professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte.

Ewing sarcomas, also known as Ewing’s sarcomas, affect 1 out of every 1 million Americans. This is a condition that predominantly affects children and young adults, but is not limited to that age group. This is a family of conditions that are related to one another.

Ewing sarcoma typically affects people between the ages of 10 and 15. About 80% of people with Ewing sarcoma are under the age of 18. Fewer than 1% of Ewing sarcoma diagnoses affect patients over the age of 40. However, it may affect people of any age.

What Is Ewing Sarcoma?

Ewing sarcoma is an extremely rare cancer that originates in the bones or, less commonly, nearby soft tissues. Typically, tumors form in the pelvis (hip bones), upper arm (humerus) or legs (middle of the long bones). Ewing sarcoma was named after the American pathologist James Ewing, who first described the condition.

Ewing Sarcoma Versus Osteosarcoma

Osteosarcoma and Ewing sarcoma, both types of sarcoma, are the most common childhood bone tumors, but there are differences between the two. Here’s a comparison.

Osteosarcoma: This is the most common type of pediatric bone tumor, although it may affect adults as well. Two age groups are most commonly affected by this condition: Those between the ages of 10 and 30 and those between the ages of 50 and 70. It may occur in patients of any age, but it most frequently occurs in those of these two groups. Any bone in the body may be affected, although the bones near the knee or elbow are frequently involved.

Ewing sarcoma: Ewing sarcoma is less common than osteosarcoma. The disease typically occurs in children and young adults between ages 10 and 15, but may affect people of any age. Most commonly, the disease arises within the bones of the ribs, pelvis or legs. It may extend beyond the bone into the nearby soft tissues of the body. In addition, this condition may also occur within the soft tissues, and is then referred to as “extraskeletal,” meaning outside of the skeleton. The two forms of disease are, however, treated the same.

What Causes Ewing Sarcoma?

The cause of Ewing sarcoma is not clear, but researchers link certain non-inherited chromosome changes to these tumors. Most often, when chromosomes 22 and 11 swap genetic material (translocation), a gene called EWSR1, which provides the code for a specific protein, is altered in a way that the protein is always activated or turned on. The uncontrolled activity of the EWSR1 protein is thought to be linked to Ewing sarcoma. The presence of this alteration also helps doctors diagnose the condition. Some patients appear to have Ewing sarcoma, but alterations in the EWSR1 protein are not present. In these patients, other alterations may give rise to the condition. Study of these cancers, called “Ewing family tumors,” is an area of active research.

Risk Factors

Several factors may put someone at a higher than average risk for developing Ewing sarcoma. These include those listed below.

Age: Ewing tumors typically affect teenagers and older children. However, patients of all ages may be affected by these conditions.

Race/ethnicity: Ewing tumors are more likely to develop in white people than Black and Asian people.

Sex: Slightly more males than females develop Ewing tumors.

Ewing Sarcoma Symptoms and Signs

The symptoms of Ewing sarcoma, or any cancer, depend on a variety of factors. These include the location of the cancer, its growth rate, and the overall health of the patient in whom it is developing. Most of the time, Ewing sarcoma develops in a bone. When this happens, the following symptoms may be experienced:

• Pain that becomes increasingly worse
• Lump or swelling
• Tenderness in the affected bone
• Loss of appetite or weight loss
• Fever
• Fatigue
• An unexpected bone break

These symptoms may be caused by many other conditions and are not specific to Ewing sarcoma. If patients experience other symptoms that do not improve, they should seek medical attention to evaluate them.

Tests for Diagnosing

The care team performs a series of tests if a patient has signs or symptoms of Ewing sarcoma. These include:

• A complete medical history and comprehensive physical exam to look for signs of disease
• One or more imaging tests — such as an X-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET) scan or bone scan — which use x-rays, magnetic fields and radioactive substances to see tumor location and size
• A biopsy, which removes a tumor sample for lab examination and testing to confirm a Ewing sarcoma diagnosis

Ewing Sarcoma Types

As noted above, there are at least two main types of Ewing family tumors:

Ewing sarcoma of bone: This is the most common type of this condition. It begins in the patient’s bone.

Extraosseous or Extraskeletal Ewing tumor (EOE): EOE may start in soft tissues around bones or in soft tissues without association to a specific bone. In the past, a condition known as “primitive neuroectodermal tumor” (PNET) was thought to be a related, but distinct condition from Ewing sarcoma. Studies looking at the EWSR1 gene have indicated that PNETs are similar or identical to Ewing sarcoma, but do not arise in the bone.

Stages

Assessing the extent of cancer — how much there is and where it has spread — is called staging, a key step in determining treatment options and prognosis.

Ewing sarcomas are typically classified as:

• Localized, meaning the cancer has not spread to other areas of the body
• Metastatic, meaning the cancer cells have spread to distant parts of the body.

EOE Staging

If the patient has an extraosseous Ewing tumor, the care team determines the stage, based on the American Joint Committee on Cancer’s staging system for soft tissue sarcoma, which uses the TNM system:

• T stands for main tumor size and location
• N stands for cancer spreading to the lymph nodes
• M stands for metastasis to other parts of the body

If the care team takes a sample during the biopsy, the tumor may also be assessed as grade 1, 2 or 3. While the stage describes the size of the tumor and whether it has spread, the grade refers to what the cancer cells look like.

All Ewing tumors are considered high-grade, meaning they look more abnormal and are more likely to grow and spread rapidly. Within the AJCC system, the care team may use these four factors (T, N, M, G) to establish an overall EOE stage.

Ewing Sarcoma Treatment

Treatment for Ewing sarcoma depends on the tumor size, origin, stage and other factors. Whether the patient is diagnosed with early or advanced cancer, it’s important to seek experts who specialize in sarcoma.

In most cases of Ewing sarcoma, chemotherapy is the first treatment. Surgery and/or radiation therapy follows, typically followed by more chemotherapy.

Chemotherapy

When a patient is diagnosed with Ewing sarcoma, the disease has typically already spread to distant parts of the body at the time of diagnosis, even if it cannot be detected except where it started. For this reason, chemotherapy, in which medicines to treat the cancer are administered and go to all parts of the body, are a critical part of treating this condition. Nearly all patients with Ewing sarcoma will be advised to receive a combination of several chemotherapy drugs.The treatments are somewhat complex and best administered by doctors experienced in the treatment of this condition. The total period of treatment may be as long as six to 12 months.

Radiation Therapy

Whether used with surgery, or instead of surgery, radiation therapy may sometimes be effective in treating Ewing sarcomas, which are very sensitive to radiation. In either situation, chemotherapy is usually given before, during and afterward.

No matter the type of radiation therapy technique they use, radiation therapists focus on killing the cancer cells with precision, while sparing healthy tissue.

Surgery

Surgery comes into play for most Ewing sarcomas for two reasons: to diagnose the disease with a biopsy and to remove the cancer.

When determining the type of surgery, doctors assess various factors, including tumor size and location, the patient’s age and general health, the likelihood of removing the tumor with clean margins and impact to function of the affected body part.

Who Treats Ewing Sarcoma?

Treating an uncommon cancer is complex. That’s why it’s important to seek specialized care — multidisciplinary specialists with experience in Ewing sarcoma, who are equipped with the latest disease-specific treatments, technologies and clinical trials. The care team may include:

• Medical oncologists, who treat cancers, such as sarcomas, with chemotherapy and other drugs.
• Pediatric oncologists, who treat cancers with chemotherapy and other drugs. They specialize in helping children, adolescents and young adults.
• Surgical oncologists, who diagnose and treat sarcomas with surgery. Surgical oncologists focus on cancers that do not involve the bones.
• Orthopedic oncologists, who specialize in using surgery to treat cancer involving the bones. In particular, reconstructive surgeries to maximize function after treatment is a major focus of their work.
• Radiation oncologists, who use radiation therapy to destroy cancerous tissue.
• Pathologists, who examine tissue samples to make sure the diagnosis is correct and to identify other information that may help determine a treatment plan.
• Radiologists, who use imaging tools, such as X-ray machines, CT scanners, MRI scanners and PET scanners to visualize cancers and determine their extent.
• Interventional radiologists, who use imaging techniques such as X-ray machines, and scanning machines (CT, MRI) in order to undertake procedures that aid the diagnosis and management of cancer. For example, interventional radiologists often undertake biopsies to obtain a specimen of a tumor for diagnosis.
• Supportive care providers, who focus on cancer- and treatment-related side effects and symptom management

Ewing Sarcoma Survival Rate

When discussing survival rates, it’s important to understand that many factors may affect the overall outlook.

Survival rates for Ewing sarcoma are grouped based on the stage, or how far the cancer has spread, when it’s first diagnosed. These numbers are rough estimates.

Scientists may describe the patient’s prognosis using five-year relative survival rates. This refers to the number of patients likely to live at least five years, compared to people without that type of cancer. The overall five-year relative survival rate for Ewing sarcoma is 65%.

Researchers further classify survival statistics based on how far the cancer has spread, as listed below.

Localized Ewing sarcoma: The five-year relative survival rate is 81% for people whose cancer hasn’t spread outside of the site of origin.

Regional Ewing sarcoma: The five-year relative survival rate is 77% for people whose cancer has spread to nearby structures or lymph nodes.

Distant Ewing sarcoma: The five-year relative survival rate is 41% for people whose cancer has spread to distant sites.

A personalized evaluation and treatment plan will be developed for each patient, taking into account these various factors.