BACKGROUND: Clinical evidence for metastatic disease at the time of diagnosis is an indicator of poor prognosis in Ewing's sarcoma. Patients with non-metastatic disease at presentation are thought to have a better prognosis than those with metastatic disease. Unfortunately, patients who appear non-metastatic at presentation may relapse after initiating or completing standard therapy for Ewing's sarcoma. Evidence of metastatic disease may be determined by radiographic studies and biopsy of potential site(s) of disease. It is possible to identify submicroscopic Ewing's sarcoma cells in blood and bone marrow, yet the prognostic value of this finding is unclear.

OBJECTIVES: To determine the incidence of RT PCR positivity in the blood and bone marrow of patients enrolled on COG AEWS0031 and to correlate the clinical outcome with RT PCR positivity.

ELIGIBILITY: Concurrent enrollment on COG AEWS0031.

DESIGN: This is a Companion Biology Study, enrolling approximately 500 patients. All specimens will be evaluated for translocations, it is anticipated that approximately 30% of specimens will have RT PCR positivity. Specimens are collected at the time of diagnosis, prior to cycle 2 chemotherapy, prior to initiation of local control, and at the end of therapy/follow up. Batched specimens are provided to the NIH by the Cooperative Human Tissue Network (CHTN). Following the completion of the COG trial and appropriate follow up periods, RT PCR positivity will be compared with clinical outcome to determine prognostic value.