Pediatric Ewing Sarcoma

What is pediatric Ewing sarcoma?

Pediatric Ewing sarcoma is a rare cancer that typically involves the bones or the soft tissues surrounding the bones. It can occur in any bone, but it most frequently occurs in the hipbones and leg bones. Less frequently, ES can be found in the upper arms, shoulder blade, ribs, spine or skull bones. ES can start in the soft tissues that surround the bone. If ES has spread in the body (by a process called metastasis), it will most commonly spread to the lungs, distant bones or to the bone marrow.

ES is not an inherited cancer that is passed down from generation to generation. It is caused by genetic changes that have occurred in the cancer cells themselves. Most commonly, ES is the result of an abnormal joining of two genes that are normally separate.

The differences between pediatric and adult ES are many, and many of the differences are not well defined. It is important to know that pediatric and adult cancers should not be compared directly (diagnosis, treatment and outcome) as they are very different diseases with the same name.

Even though pediatric ES is the second most common pediatric bone cancer and makes up 2 to 4 percent of all childhood tumors, it remains rare overall.

Pediatric ES comprises a group of bone and soft tissue tumors known as the Ewing family of tumors that share a number of molecular and genetic characteristics but originate from different locations and may be treated differently. This group includes:

Ewing sarcoma of the bone. This is the most common tumor in the Ewing family.
Extraosseous Ewing sarcoma (EOE). This rare type of tumor originates in the soft tissue surrounding the bone. It most frequently affects the chest and back, arms and legs, head and neck or tissue behind the abdomen.
Askin tumors. These tumors affect the chest wall.
Peripheral primitive neuroectodermal tumors (pPNET). This is a rare cancer that is similar to Ewing sarcoma of the bone and EOE.

What are the symptoms of pediatric Ewing sarcoma?

Symptoms of pediatric ES may include

Pain in the area of the tumor that does not improve at night (the most common symptom)
Paresthesia (pins and needles, numbness) if the tumor is pushing against nerves
A mass or lump that can be felt and may be warm and/or tender to the touch
Fever of an unknown source
A broken bone without good reason

Less frequent symptoms include weight loss, infection and generalized bone pain.
Symptoms develop as the tumor grows. Some children will develop symptoms early, while others may not develop noticeable symptoms. Children who do not develop symptoms may be diagnosed when their doctor is performing an exam or test for another condition.

Many of the symptoms of pediatric ES are similar to common complaints in an active child or adolescent, making the diagnosis of ES difficult based on symptoms alone. Most children will experience symptoms on average for three to nine months prior to being definitively diagnosed.

Both boys and girls can be diagnosed with ES, but boys are diagnosed slightly more often than girls. Caucasian children develop ES more frequently than Asian-American or African-American children. Although ES can be diagnosed at any age, the majority of cases are diagnosed between 10 and 20 years of age for both boys and girls. ES is uncommon in children who are less than 5 years old, but it has been known to occur in this age group.

How is pediatric Ewing sarcoma diagnosed?

If your child has symptoms of ES, the doctors at Riley at IU Health can perform the following exams and tests to make a diagnosis:

Physical examination. Diagnosing pediatric ES typically begins with a physical examination by your child’s doctor. Any abnormal findings may be further evaluated if there is concern for a tumor.
X-ray. X-ray images of a concerning area are often the next step in diagnosing a tumor. In some cases, X-rays will demonstrate findings consistent with a growth in or near the bone, or they will demonstrate abnormal breaks in a child’s bones that warrant further evaluation.
Magnetic resonance imaging (MRI). MRI is an imaging procedure that uses a magnetic field instead of radiation to show tumors in bone, muscle and soft tissue. MRI allows doctors to evaluate the area of concern in greater detail.
Computed tomography (CT). CT creates multiple detailed or three-dimensional images of bone, tissue and blood vessels. Doctors may also use this fast, painless imaging procedure to evaluate the area of concern.
Blood tests. A blood test may be ordered to look at the red blood cells, white blood cells, platelets and blood chemistries that can be affected in children with cancers.
Biopsy. Ultimately, a sample of the tumor itself (biopsy) is needed to confirm the diagnosis of pediatric ES. Depending on the location and size of the tumor, a biopsy can either be done with a needle, by surgical removal of a small piece of the tumor or, in some cases, by surgical removal of the entire tumor. The pieces of tumor are then specially prepared and placed on microscope slides for evaluation by the pathologist who provides a final tissue diagnosis.

Once a tumor has been diagnosed as ES, the cancer team will obtain additional tests to determine if the tumor has spread to other areas of the body. This is called staging and may include:

Chest X-ray
Bone scans
Additional MRI or CT imaging
Bone marrow biopsy
Bone marrow aspiration

How is pediatric Ewing sarcoma treated?

The treatment of ES is likely to include a combination of:

Chemotherapy. Chemotherapy is when medicines are provided by mouth or intravenously to destroy cancer cells.
Radiation therapy. High-energy radiation is directed on the tumor to shrink or destroy it or to kill cancer cells.
Surgery. The tumor and/or affected bone or tissue may be removed depending on the location and advancement of ES.

The choice of therapies, timing and duration will be chosen by a team of oncologists (cancer doctors) based on the original site of the tumor and whether it has spread at the time of diagnosis.

A number of factors can influence a child’s long-term outlook, including:

Extent of the condition (whether the tumor has spread to nearby or distant sites in the body)
Location of the initial tumor
Size of the tumor at diagnosis
Tumor genetics
Patient’s age and gender
Tumor response to therapy
Whether the tumor was completely removed

In general, the overall five-year survival for localized ES (that has not spread at the time of diagnosis) is favorable. About 70 percent of children are alive at five years after their diagnosis. Because this percentage is based on survival after five years, it does not reflect the improved prognosis that can come from recent improvements in treatment.

Key Points to Remember

Pediatric Ewing sarcoma (ES) is a form of cancer/tumor that primarily affects children and young adults.
Pain in the area of the tumor that does not improve at night is the most common symptom.
Many symptoms of ES are similar to common complaints in an active child or adolescent, making a diagnosis difficult based on symptoms alone.
Ultimately, a sample of the tumor itself (biopsy) is needed to confirm the diagnosis of ES.
Therapy will likely include a combination of chemotherapy, radiation therapy and surgery.

Support Services & Resources

Visit the trusted websites below to learn more about ES.

Riley at IU Health offers a broad range of supportive services to make life better for families who choose us for their children's care.

Learn More About Riley Support Services

National Cancer Institute

The National Cancer Institute shares general information about ES on its website, including the stages of the condition.

American Society of Clinical Oncology

The American Society of Clinical Oncology provides an in-depth overview of ES in children.

Pediatric Ewing Sarcoma Research

Riley at IU Health is a member of the Children's Oncology Group Phase 1 & Pilot Consortium, an organization that is dedicated to researching and finding new treatments for childhood cancer. The National Cancer Institute also sponsors some of the cancer research we do at Riley at IU Health. Ask your child's doctor for more information about current research studies or clinical trials on ES or visit ClinicalTrials.gov. Please note: Not all clinical trials may be applicable to pediatric patients or your child's type or stage of cancer. Please consult your child's doctor with questions regarding available trials.

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