Extraosseous localized Ewing tumors: Improved outcome with anthracyclines - The French Society of Pediatric Oncology and International Society of Pediatric Oncology

Purpose To evaluate the outcome of children with an extraosseous Ewing tumor (EOE) according to treatment. Patients and Methods Children with EOE were treated either with the strategy used for malignant mesenchymal tumors (MMTs) by the International Society of Pediatric Oncology ( SIOP) or with the French Society of Pediatric Oncology (SFOP) regimen used for osseous Ewing tumors (OET). The MMT strategy included vincristine/ actinomycin for small and resected tumors or ifosfamide/ vincristine/ actinomycin for unfavorable sites or unresectable tumors. Surgical excision was to be attempted after four courses, followed by local irradiation in case of residue. Osseous Ewing (OE) protocol included three courses of cyclophosphamide/ doxorubicin followed either by two similar courses in case of good response or two courses of ifosfamide/ etoposide in case of no response. After resection of the primary, treatment included conventional chemotherapy in case of good histologic response and high-dose chemotherapy and radiotherapy for poor response. All diagnosis specimens were reviewed by the panel. Results Between 1989 and 1999, 63 patients were registered. Characteristics of patients treated by both protocols were similar. Five-year overall survival ( OS) and event-free survival (EFS) of those treated with the OE protocol are 83% and 75%, respectively, which is significantly better than the OS and EFS of those treated with the MMT strategy (59% and 44%, respectively; P =.04 and .008, respectively). The size of the primary and the type of protocol influenced patients' EFS. In multivariate analysis, only the regimen had an impact on OS and EFS. Conclusion Our study shows that patients with EOE should be treated with OE regimens, probably because of the use of anthracyclines.