Extraskeletal Ewing's sarcoma

BACKGROUND Ewing's sarcoma usually is identified as a primary malignancy of bone affecting children and young adults. Extraskeletal Ewing's sarcoma is rare, and very few data are available addressing optimal surgical and oncologic treatment modalities. METHODS The authors chose to review retrospectively 24 patients with extraskeletal Ewing's sarcoma treated at the study institution with modern multimodality therapies. Anatomic location, tumor size, patient age at diagnosis, stage of disease at the time of diagnosis, surgical margins, radiation dose, and the type and dose of chemotherapy were documented for every patient. Follow-up averaged 64 months for surviving patients. RESULTS The overall 5-year survival rate was 61% and the disease free survival rate was 54%. A multivariate analysis found that younger age at the time of diagnosis was associated with improved 5-year survival and disease free survival (P = 0.008 and P = 0.005, respectively). Patients who underwent wide resection and less-than-wide resection had better overall survival (P = 0.001 and P = 0.015, respectively) and disease free survival (P = 0.002 and P = 0.024) compared with those who underwent no attempt at surgical resection. Patients who underwent a wide resection had an improved overall survival compared with those who underwent a less-than-wide resection (P = 0.045). The size of the lesion (P = 0.277) and the presence of metastatic disease at the time of diagnosis (P = 0.219) were not found to be significant prognostic factors. CONCLUSIONS Age and surgical treatment were found to be important prognostic variables in the treatment of extraskeletal Ewing's sarcoma. No other variables, such as tumor size, tumor location, stage of disease, or radiation therapy, were found to improve survival. Surgical resection should be considered for all patients with extraskeletal Ewing's sarcoma. Cancer 1999;85:725–31.