ABSTRACT
Ewing sarcoma is the second most frequently occurring malignant tumor of the bone and soft tissue in adolescents and young adults. Genetically, Ewing sarcoma is characterized by balanced chromosomal translocation in which a member of FET gene family is fused with an ETS transcription factor, with the most common fusion being EWSR1-FLI1 (85% of cases). Treatment of Ewing sarcoma is based on multidisciplinary approach (local surgery, radiotherapy and multiagent chemotherapy), which are associated with chronic late effects that may compromise quality of life of survivors. First line treatment includes combination of drugs incorporating doxorubicin, vincristine, cyclophosphamide, ifosfamide, etoposide, and dactinomycin. The beneficial role of high dose chemotherapy has been suggested in high-risk localized Ewing sarcoma patients, and the studies are being performed to investigate the role in metastatic disease. The 5-year overall survival for localized Ewing sarcoma has improved to reach 65% to 75%. But patients with metastatic disease have a 5-year survival rate of <30%, except for those with isolated pulmonary metastasis (approximately 50%). Patients with recurrent tumor have a dismal prognosis. Novel therapeutic strategies based on understanding of molecular mechanisms are needed to improve the outcome of Ewing sarcoma and to lessen the treatment-related late effects.