Long-term Outcomes and Complications in Pediatric Ewing Sarcoma

Abstract
The objective of this study was to determine treatment outcomes and long-term complications in pediatric patients with Ewing Sarcoma treated at the British Columbia Cancer Agency (BCCA).A retrospective chart review of 101 pediatric patients (<19 y old) with Ewing Sarcoma diagnosed between 1960 and 2005 was performed. The Kaplan-Meier survival analysis and Cox regression multivariate analysis were used to assess prognostic factors for overall survival (OS) and event-free survival (EFS).The median age at diagnosis was 11 years and the median follow-up for nondeceased patients was 13.5 years. The most common primary tumor locations were lower extremity (33%), pelvis (24%), and thorax (18%). Fifty percent of patients received surgery, 79% radiotherapy and 94% chemotherapy. The 5-year OS and EFS for patients with localized disease was 85% and 73% and for metastatic disease was 27% (P<0.0001) and 28% (P<0.0001), respectively. Metastatic disease was an independent predictor of lower OS (hazard ratio [HR], 9.5; 95% confidence interval [CI],4.7-19.4; P<0.0001) and EFS (HR, 4.9; 95% CI, 2.7-8.8; P<0.0001). Extremity tumor location was an independent predictor for improved OS (HR, 0.4; 95% CI, 0.2-0.9; P=0.03). The majority (77%) of long-term survivors (≥5 y) had long-term complications; the most common were musculoskeletal abnormalities (50%) and cardiac toxicity (28%). The actuarial second neoplasm risk was 5% at 10 years.Ewing sarcoma patients with localized disease had excellent treatment outcomes at the BCCA. However, the majority of patients had chronic complications from treatment. This study validates the need for long-term follow-up of Ewing Sarcoma survivors for management of late effects.