Local Control Modality and Outcome for Ewing Sarcoma of the Femur: A Report From the Children’s Oncology Group

Background: The choice of a local control (LC) modality for Ewing sarcoma (EWS) of the femur is controversial. This study aimed to determine the effect of LC modality on tumor LC and patient outcomes. Methods: The study reviewed the treatment and outcomes for 115 patients who had EWS of the femur treated with similar chemotherapy in three cooperative group trials. Patient outcomes were analyzed according to the LC modality using the log-rank test and the cumulative incidence of local or distant failure using competing risks regression. Results: The median age of the patients was 13 years. The most common tumor location was the proximal femur followed by the mid femur. For 55 patients with available data, the tumor was larger than 8 cm in 29 patients and 8 cm or smaller in 26 patients. For 84 patients (73 %), surgery only was performed, whereas 17 patients (15 %) had surgery plus radiation, and 14 patients (12 %) had radiation only. The 5-year event-free survival (EFS) rate was 65 % (95 % confidence interval [CI], 55–73 %), and the 5-year overall survival (OS) rate was 70 % (95 % CI, 61–78 %). Patient outcomes did not differ significantly according to tumor location within the femur (proximal, mid or distal) or tumor size (<8 vs ≥8 cm). The findings showed no statistically significant differences in EFS, OS, cumulative incidence of local failure, or cumulative incidence of distant failure according to LC modality (surgery, surgery plus radiation, or radiation). Conclusions: The LC modality did not significantly affect disease outcome for EWS of the femur. Further study of treatment complications and functional outcome may help to define the optimal LC modality.