Ewing sarcoma: prognostic criteria, outcomes and future treatment.

Ewing sarcoma (EWS) is a bone tumor occurring primarily in adolescence and young adulthood. Multi-institutional clinical trials have improved the outcome for patients with nonmetastatic EWS, but not with metastatic EWS. Furthermore, although 30% of EWS recur, multi-institutional studies have not been completed for this high-risk group. Planning such studies has been hampered by both the lack of novel therapies and the inability to incorporate the biology of EWS. While the importance and detail of the EWS-FLI-1 translocation between chromosomes 11 and 22 are described, these have not yet led to new drug development for this orphan tumor. However, recent evidence supporting novel cytotoxic therapy, antiangiogenic therapy, and receptor-targeted therapy provides reason for optimism for patients with high-risk disease.