A prognostic score at diagnosis for Ewing tumor patients with metastatic disease at extrapulmonary sites

Abstract

10544 Background: To assess prognostic factors at diagnosis in prospectively treated patients with primary extra-pulmonary metastatic Ewing tumors (EPM-ET) of the EURO-E.W.I.N.G. 99 Study. Methods: From 1999 to 2005, 281 patients were enrolled. Median age was 16.2 years (0.4–49). Primary site was extremity in 84 patients and axial in 197 (115 pelvic sites), with a tumor volume >200ml in 171 patients. Treatment consisted of 6 VIDE cycles, one VAI/VAC cycle, local treatment (surgery and/or radiotherapy), and high-dose busulfan-melphalan followed by peripheral stem cell transplantation (HDT/SCT). Results: After a median follow up of 3.8 years, event-free survival (EFS) and overall survival (OS) at 3 years for all 281 patients were 27%±3% and 34%±4%. Six VIDE cycles were completed by 250 patients (89%); 169 (60%) received HDT/SCT. Cox regression analyses demonstrated increased risk for patients with more than two bone metastatic sites (hazard ratio: HR 2.0), a primary tumor volume >200ml (HR 1.8), bone marrow metastases (HR 1.6), age >14 years (HR 1.6), and additional lung metastases (HR 1.5). A risk score based on these HR identified three risk groups with EFS rates of 50% for scores <_3 (82 patients), 25% for scores >3 to <5 (102 patients), and 10% for scores >_5 (70 patients), p< 0.0001. Conclusions: A proportion of EPM-ET patients may survive with intensive multimodal therapy. Age, tumor volume, and extent of metastatic spread are relevant risk factors. A score based on these factors identifies EPMD-ET patients with a more favorable outlook at diagnosis and may facilitate risk adapted treatment approaches. No significant financial relationships to disclose.