Role of radiation in the treatment of non-metastatic osseous Ewing sarcoma.

Abstract

Local control, either with surgery, radiation (RT) or both, is essential in the management of localised Ewing sarcoma; however, the relative role of RT remains controversial. Using the Surveillance, Epidemiology, and End Results database, 612 patients treated for non-metastatic skeletal Ewing sarcoma between the years 1988 and 2010 were identified. Median age and follow-up were 13 years (range: 0-21) and 56 months (range: 0-287), respectively. Five-year overall survival (OS) for the cohort was 74.4 ± 2.0%. Patients received surgery alone (51.3%), RT alone (21.6%) or both (27.1%). Patients with skeletal Ewing sarcoma had improved OS with surgery alone compared with other treatments. However, in subset analyses, RT was not inferior to surgery alone for appendicular (5-year OS: 80.0% vs. 79.3%), non-pelvic (84.3% vs. 79.9%) or localised disease (confined to cortex or periosteum; 79.7% vs. 80.6%). After controlling for stage and site, no increase in mortality was observed with RT versus surgery alone (hazard ratio = 0.77 (95% confidence interval: 0.49-1.19)). In regard to survival, RT did not appear to be inferior to surgery alone for most patients, particularly those with disease at favourable sites (localised, appendicular, non-pelvic). In select patients with Ewing sarcoma, RT may be an appropriate strategy for local control that does not necessarily compromise survival outcomes.