It is clear that improved understanding of the basic biology of Ewing sarcoma will ultimately lead to improved treatment for this disease. The EWS-ETS fusion gene has already been identified in these tumors. The search for new genes is ongoing with hopes of identifying new molecular targets for future drug development. This study is designed to analyze biological factors of Ewing sarcoma and to relate the tumor characteristics to treatment outcome.

This study will also establish a bank of Ewing sarcoma tissue.

There will be no additional procedures performed as part of this study. The specimens will be collected while the patient is undergoing regular diagnostic and treatment procedures. The samples to be collected include:

• A piece of the tumor (the amount depends on the size of the tumor) at diagnosis, second surgery (if applicable) and if the tumor returns after treatment
• A teaspoon of bone marrow from the diagnostic procedure
• 3 teaspoons of blood at diagnosis, before the second cycle of chemotherapy, before any local therapy (i.e., radiation and/or second surgery), end of treatment and relapse (if applicable) for a total of 5 samples (5 tablespoons)

The samples will be sent to the Pediatric Cooperative Human Tissue Network (PCHTN) where they will be distributed out to the individual researchers investigating the biological factors of Ewing sarcoma. If there is any tissue left over after the distribution, the patient has the option of either having the remaining sample destroyed or having it banked into a new Ewing sarcoma tissue bank where it can be used in future research studies.