Role of radiotherapy in the multimodal treatment of Ewing sarcoma family tumors

Purpose The aim of this study was to evaluate the role of radiotherapy (RT) in the management of Ewing sarcoma family tumors (ESFT). Materials and Methods Retrospective analysis was performed on 91 patients with localized ESFT treated from 1988 to 2012. Primary tumor size was ≥ 8 cm in 33 patients. Surgery, RT, and combined surgery with RT were applied in 37, 15, and 33 patients, respectively. Results Median follow-up was 43.8 months. Forty-three patients (47.3%) showed recurrence or progressive disease. Twelve patients (13.2%) showed local failure after initial treatment. Thirty-nine patients (42.9%) experienced distant metastases. The 5-year overall survival (OS), progression-free survival, and local control (LC) were 60.5%, 58.2%, and 85.1%, respectively. According to treatment, 5-year LC was 64.8% with RT and 90.2% with combined surgery and RT (p=0.052). Prognostic factors for OS were tumor size (≥ 8 cm, p < 0.001) and surgical resection (p < 0.001). In large tumors (≥ 8 cm), combined surgery and RT produced better LC compared to RT (p=0.033). However, in smaller tumors (< 8 cm), RT without surgery resulted in a similar LC rate as RT with surgery (p=0.374). Conclusion RT used for patients with unfavorable risk factors resulted in worse outcome than for patients who received surgery. Smaller tumors could be controlled locally with chemotherapy and RT. For large tumors, combined surgery and RT is needed. Proper selection of local treatment modality, RT, surgery, or both is crucial in the management of ESFT.