Treatment results of the Ewing sarcoma of bone and prognostic factors.

Background: The purpose of this study is to assess the clinical outcome of patients with ESFT of the bone treated with the European Intergroup Cooperative Ewings Sarcoma Study (EICESS)-92 treatment protocol at a single center, and to identify prognostic factors.

Methods: Ninety-eight patients younger than 18 years of age, diagnosed with ESFT of the bone between 1992 and 2005, were analyzed retrospectively.

Results: Eighty-seven patients were treated with the EICESS-92 protocol. The median follow-up was 105 +/- 38 months. The 5-year event-free survival (EFS) survival rate was 40%, the 5-year overall survival (OS) rate was 47%. For non-metastatic disease, the rates of 5-year EFS and OS were 45% and 51%. These rates were 18% and 27%, for metastatic disease. The 5-year EFS and OS rates were 17% and 30%, respectively for females. For males, theses rates were 45% and 48%. Of 87 patients, 52 were admitted with primary extremity lesions. Distant metastasis was detected in 48% of patients with a metaphyseal tumor. In patients with diaphyseal lesions, it was 17%. The 5-year EFS and OS were 35% and 43%, respectively. In non-metastatic disease, these measures were 43% and 50%, whereas in metastatic disease, they were 20% and 27%. In patients with a lesion originating from metaphysis, the 5-year EFS was 17%, and the 5-year OS was 29%, for patients with a diaphyseal lesion, these values were 50% and 54%.

Conclusion: The presence of metastasis was closely related with metaphyseal tumors. The localization of tumor in the bone (i.e., diaphyseal or metaphyseal) and gender of patients seem to have prognostic importance.