Diagnosing Ewing Sarcoma
Many children are diagnosed after their primary care doctor ordered or performed imaging studies such as X-rays, CT Scans or MRI tests. These imaging studies sometimes need to be repeated by oncology specialists. If doctors suspect a bone or soft tissue tumor, the physician will ensure that the child is diagnosed and treated by a team experienced in dealing with children with cancer, and particularly bone and soft tissue cancers.
The most important evaluation of the tumor is the biopsy. In this test, a sample of tumor tissue will be removed from the site and examined under a microscope by a pathologist. It is best if the biopsy is done by an orthopedic oncologist, surgeon or radiologist who will be involved in the care of the patient. There are often special tests required on the biopsy not available at all institutions.
Determining the Extent of Disease
In patients with Ewing Sarcoma, 10% to 30% have metastatic disease at the time of diagnosis, meaning the cancer has spread to other areas. Staging the disease – determining how far it has spread – is very important because it helps the healthcare team make the best, most informed decisions about treatment.
In order to determine the extent and spread of the disease, many doctors will perform some or all of the following examinations:
- CT scan or MRI of the primary tumor
- Chest x-ray
- CT scan of the chest
- Bone scan
- Bone marrow aspirate and bone marrow biopsy
- PET scan
For tumors like Ewing sarcoma, the extent of the disease at diagnosis is the most important factor in determining the prognosis (chance of recovery). Other factors include:
- Primary site (further away from the center of the body is better)
- The presence of metastasis
- Size of the tumor (larger is worse)
- Age of the child (younger tends to be better)
The survival rate for Ewing sarcoma has increased 30% since 1975. Today, over 70% of children diagnosed with non-metastatic Ewing sarcoma are cured. For patients whose cancer has metastasized, the survival rate tends to be lower.
Causes of Ewing Sarcoma
While researchers now know more about genetic markers in the Ewing sarcoma tumors, we still do not know much about why certain children develop this cancer. We do know, however, that Ewing sarcoma is not associated with any other cancers and there is no additional risk among families in which a single person has Ewing Sarcoma.