Ewing sarcoma

What is Ewing sarcoma?

Ewing sarcoma is a cancer that occurs primarily in the bone or soft tissue. Ewing sarcoma can occur in any bone, but is most often found in the extremities and can involve muscle and the soft tissues around the tumor site. Ewing sarcoma cells can also spread (metastasize) to other areas of the body including the bone marrow, lungs, kidneys, heart, adrenal gland and other soft tissues. This type of bone tumor accounts for about 30 percent of pediatric bone cancers.

Ewing sarcoma most often occurs in children between the ages of 5 and 20. Prior to adolescence, the number of males and females affected are equal. After adolescence, however, the number of males affected is slightly higher than the number of females. It has been suggested that the increased rate of growth among males during adolescence may account for this increased incidence.

What causes Ewing sarcoma?

The majority of Ewing sarcomas result from a chromosome rearrangement between chromosomes #11 and #22. This rearrangement changes the position and function of genes, causing a fusion of genes referred to as a "fusion transcript." Over 90 percent of individuals have an abnormal fusion transcript, involving two genes known as EWS and FLI1. This important discovery has led to improvements in diagnosing Ewing sarcoma.

Similar to osteogenic sarcoma, trauma or injury sometimes is involved with the site at the time of diagnosis. However, this trauma is thought to bring the condition to attention rather than to have any causal relationship.

Some physicians classify Ewing sarcoma as a primitive neuroectodermal tumor (PNET). This means the tumor may have started in fetal, or embryonic, tissue that has developed into nerve tissue.

What are the symptoms of Ewing sarcoma?

The following are the most common symptoms of Ewing sarcoma. However, each child may experience symptoms differently. Symptoms may include, but are not limited to the following:

• Pain around the site of the tumor.
• Swelling or redness around the site of the tumor.
• Fever.
• Weight loss, decreased appetite.
• Fatigue.
• Paralysis and/or incontinence (if the tumor is in the spinal region).
• Symptoms related to nerve compression from tumor (i.e., numbness, tingling, paralysis, etc.).

The symptoms of Ewing sarcoma may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.

How is Ewing sarcoma diagnosed?

In addition to a complete medical history and physical examination of your child, diagnostic procedures for Ewing sarcoma may include:

• Multiple imaging studies, such as:
  • X-rays: A diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
  • Bone scans - a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation.
  • Magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.
  • Computed tomography scan (Also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat and organs. CT scans are more detailed than general x-rays.
• Blood tests (including blood chemistries).
• Bone marrow aspiration/biopsy (to detect cancer cells) - a procedure that involves a small amount of bone marrow fluid and tissue to be taken, usually from part of the hip bones, to further examine the number, size and maturity of blood cells or abnormal cells.

Ewing sarcoma is difficult to distinguish from other similar tumors. Diagnosis is often made by excluding all other common solid tumors and by the use of genetic studies.

Treatment for Ewing sarcoma

Specific treatment for Ewing sarcoma will be determined by your child's physician based on:

• Your child's age, overall health and medical history.
• Extent of the disease.
• Your child's tolerance of specific medications, procedures or therapies.
• Expectations for the course of the disease.
• Your opinion or preference.

Treatment may include one, or more, of the following

• Surgery.
• Chemotherapy.
• Radiation therapy.
• Amputation.
• Resections for metastases (i.e., pulmonary resections of cancer cells in the lung).
• Rehabilitation including physical and occupational therapy and psychosocial adaptation.
• Prosthesis fitting and training.
• Supportive care (for the side effects of treatment)
• Antibiotics (to prevent and treat infections).
• Continual follow-up care (to determine response to treatment, detect recurrent disease and manage late effects of treatment).

Long-term outlook for a child with Ewing sarcoma

Prognosis for Ewing sarcoma greatly depends on:

• The extent of the disease.
• The size and location of the tumor.
• Presence or absence of metastasis.
• The tumor's response to therapy.
• The age and overall health of your child.
• Your child's tolerance of specific medications, procedures or therapies.
• New developments in treatment.

As with any cancer, prognosis and long-term survival can vary greatly from child to child. Every child is unique and treatment and prognosis is structured around the child's needs. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a child diagnosed with Ewing sarcoma. Late effects of radiation and chemotherapy, as well as second malignancies, can occur in survivors of Ewing sarcoma. New methods are continually being discovered to improve treatment and to decrease side effects.