Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the stages of Ewing Sarcoma ?
    ### Response:
    Key Points
                    - The results of diagnostic and staging tests are used to find out if cancer cells have spread.    - Ewing sarcoma is described based on whether the cancer has spread from the bone or soft tissue in which the cancer began.          - Localized Ewing sarcoma     - Metastatic Ewing sarcoma        - There are three ways that cancer spreads in the body.
    