Prognostic factors for overall survival in paediatric patients with Ewing sarcoma of bone treated according to multidisciplinary protocol

The purpose of this study is to assess the outcome of patients with Ewing sarcoma (EWS) of the bone and to identify prognostic factors. Seventy-seven patients younger than 18 years old, diagnosed with EWS of the bone between 1979 and 2009, were analysed retrospectively. Four different protocols of chemotherapy were used successively. Local treatment consisted of surgery (N=32), radiotherapy (N=20) and a combination of both (N=19). The median age at diagnosis was 10 years old (range, 2-17) and the median follow-up for survivors 8.6 years (range, 1-18.8). Thirty-two relapses occurred (21 distant, 5 local and 6 both). The 2- and 5-year overall survival rates were 70% and 51%, respectively. Multivariate analysis showed four significant independent predictors for death: age a parts per thousand yen14 years old (HR: 5.06; p=0.019), lack of complete response (HR: 8.04; p < 0.001), tumour volume a parts per thousand yen150 ml (HR: 2.21; p=0.045) and distant recurrences (HR: 1.45; p=0.001). Outcome of EWS of bone is influenced by many clinical and treatment-correlated variables. Criteria to stratify patients should include all the variables that have shown prognostic significance. The development of novel therapies should target these high-risk groups.