Ewing's Sarcoma |
Tumors in the Ewing's family of sarcomas are made of primitive cells, which are cells that haven't yet decided what type of cell they are. They look blue to a pathologist because of the staining that is used when identifying the cancer, so the cells are referred to as "small round blue cells," as shown in this pathologist's slide.
The Ewing's family of sarcomas includes:
- Ewing's sarcoma of the bone
- Extraosseus Ewing's sarcoma, also referred to as extraskeletal Ewing's sarcoma (tumor growing outside of the bone)
- Primitive neuroectodermal tumor (PNET)
- Peripheral neuroepithelioma
- Askin's tumor (ES of the chest wall)
- Atypical ES
Where do Ewing's Sarcoma Tumors Occur?
The Detailed Guide: Ewing's Family of Tumors states, "The majority of these tumors occur in the trunk, and the most common site is the pelvis. About one third of the bone tumors occurs in the legs, mainly in the middle of the long bones. In contrast, osteosarcoma usually occurs at the ends of the long bones, especially around the knees. The next most common sites are the ribs and spine. The extraosseous tumors can occur almost anywhere."
Drs. Daliani and Patel, in their article, "Soft-Tissue and Bone Sarcomas," state that Ewing's sarcoma "is considered a systemic disease; even when a tumor is apparently localized, approximately 90% of the cases include occult metastatic disease."
How is Ewing's Sarcoma Treated?
Currently, the treatment of Ewing's sarcoma (soft tissue tumors and bone tumors) are the same. Based on the results of a a number of clinical trials the first line treatment is quite standardized and consists of:
- 14-17 cycles of chemotherapy, alternating between 2 regimens of drugs
- Resection surgery if possible, which frequently involves limb-sparing surgery and donor bones if there is bone involvement
- Daily radiation treatments for 6 weeks to the primary site
Ewing's sarcoma is an aggressive cancer, and requires 9 months to a year to treat in the best case. If the cancer doesn't respond to "first line treatment" and if there is known disease, there are other drugs to try. If these don't work, the patient may be a candidate for a clinical trial.
Dr. Randall, in the article below this introduction, states that, "It is critical that a patient diagnosed with ESFT is treated at a center very familiar with this disease." He goes on to state, "Advances in chemotherapy (CTx) have significantly improved survival. Surgical removal of the primary tumor generally occurs after a course of initial chemotherapy. Chemotherapy is started first to attack any potential tumor cells that have broken off from the main tumor (metastasized) but have not yet been detected by the staging studies."
What is the Prognosis for Patients with Ewing's Sarcoma?
An important characterization of the cancer is whether it is local or if it has spread (i.e., metastasized). If there are no metastases at diagnosis, the 5-year prognosis is 70% for children and 50% for adults. If there are metastases, the prognosis is much lower (10-25%). The prognosis is not good for patients that develop metastases while in treatment; see our Prognosis page.
How is Ewing's Sarcoma Diagnosed?
If Ewing's sarcoma metastasizes, it normally spreads to the lungs, bones and bone marrow. Chest CT scans are performed to check the lungs. If the primary tumor was in the bone, bone marrow biopsies are performed. Bone scans check for tumors in the bones. Other scans, such as an MRI scan, angiogram, and a PET scans are also used, from time to time, for diagnostic purposes. A biopsy will be required in order for a pathologist to indicate the specific subtype of sarcoma. Either a fine needle aspiration, core need biopsy or a surgical biopsy will be performed. The tissue should be classified by a pathologist who has substantial background in diagnosing sarcomas. It is quite common to seek a second opinion from a pathologist at a cancer center that has expertise in dealing with sarcoma.
Who develops Ewing's Sarcomas?
About 75% of the cases of Ewing's sarcoma involve young patients age 5 to 20 years. Since Ewing's sarcoma has a higher incidence in children than in adults, it is considered a "pediatric cancer." The median patient age is 15 years old. There are approximately 200 new cases diagnosed in children and adolescents in the US per year (Improved Survival for Those With Ewing's Sarcoma), and 20 diagnosed in adults (European Society for Medical Oncology).
More About Ewing's Sarcoma
Dr. R. Lor Randall, Director of Sarcoma Services at the Huntsman Cancer Institute and Primary Children’s Medical Center at the University of Utah, has written an in-depth article about this disease below. We also have pages that discuss Ewing's sarcoma location, tests, treatments, prognosis and refractory or recurrent disease.