How Does the Doctor Know if a Child Has Ewing's Sarcoma? continued...
The doctor will also ask for imaging tests if a lump has been found or other symptoms of a possible tumor have been identified during the exam. The tests might include:
- X-rays to locate and identify a potential bone tumor
Magnetic resonance imaging (MRI) scan, which uses radio waves and strong magnets to create a more detailed image of a potential tumor seen on an X-ray
- Computed tomography (CT or CAT) scan to see if a tumor has spread to the lungs, liver, or lymph nodes
- Bone scan, which uses an injected radioactive material and a special camera to identify potential spots in the skeleton where the cancer may have spread
- Positron emission tomography (PET) scan, which also uses a radioactive material and special camera to identify other spots in the body that may have a tumor
If a potential tumor has been found, the doctor will then ask for a biopsy to confirm the presence of Ewing's sarcoma. During a biopsy, cells and tissue are removed and then examined in a lab. If your child is going to have a biopsy, the specialists who will be involved in treating the cancer should take part in planning it to minimize the incidence of complications and misdiagnosis. This will insure that the incision that's made to remove the tissue won't interfere with later surgery or treatment with radiation. For children, biopsies are usually done under general anesthesia.
Finally, if Ewing's sarcoma is confirmed, the results of the biopsy, lab tests, imaging tests, and physical exam will all be used to determine the stage of the cancer.
How Is Ewing's Sarcoma Staged?
Staging is a process used to determine the extent of the cancer -- whether it has spread and if so, how far. The system used for staging Ewing's Sarcoma is simpler than for a lot of other cancers. Ewing's sarcoma is classified as either localized Ewing tumors or metastatic Ewing tumors. A tumor is said to be localized only if there is no evidence of distant spread to other organs. That means it's confined to its site of origin with little spread to nearby tissues. Metastatic tumors have spread to other organs. The most common sites include the lungs, other bones, and bone marrow. It can, though, spread to other organs, including the liver and the lymph nodes.
The stage is used to help determine both the prognosis and the appropriate treatment options. The prognosis is an indication of what the likely course of the disease is and the chances that treatment will be effective. It's often stated in terms of a five-year survival rate. For patients with localized Ewing tumors, the five-year survival rate is close to 70%. For metastatic tumors, the five-year survival rate is 20% to 30%. If the cancer has spread only to the lungs, the rate is slightly better.
But survival rate is only a statistic. It does not predict what is going to happen for any one person. If your child is diagnosed with Ewing's sarcoma, keep in mind that other things beside stage can affect the prognosis. They include:
- Size of the tumor
- Where the main tumor is located
- How the tumor responds to chemotherapy
- The child's age
- The presence of a certain genetic marker that indicates better prognosis