Osseous Ewing’s Sarcoma in Children: Challenges in Local Treatment and its Impact on Treatment Outcome

Abstract

Background: Ewing’s sarcoma (ES) is the second most common primary malignant bone tumor in children. Treatment consists of systemic chemotherapy and local treatment either surgery, radiotherapy (RT) or both depending on various tumor characteristics. We evaluated the clinical characteristics and outcome of osseous ES in children. We tried to find out the limitations for providing the best possible local treatment and its impact on treatment outcome. Methods: All patients of ES ( ≤ 15 years of age at presentation) diagnosed between October 2016 to September 2019 were included in this retrospective analysis. Patients were followed up till February 2021. Results: Clinical characteristics analysis of the 39 cases of osseous ES showed 22 had a primary tumor in the axial skeleton, and 17 in the appendicular skeleton. Twenty-seven patients had localized disease, and 12 had metastasis at presentation.  Thirty patients (22 localized, 8 metastatic) were treated with curative intent.  Twenty-seven patients received RT. Eight among them had metastatic disease, 3 had chest wall ES who received RT after surgery, 9 received definitive RT for unresectable axial tumor, and 3 received RT for positive cut margin following LSS. Four patients had appendicular tumors, but could not undergo LSS because of logistic issues and received definitive RT. Only two patients could undergo LSS and didn’t require postoperative RT. The overall survival (OS) and event-free survival (EFS) at 3 years were 71% and 60% respectively, which is comparable to historical control. Conclusion: Limb salvage surgery, though is the treatment of choice, is not always feasible in developing countries. Definitive RT can achieve effective local control with outcomes comparable to patients treated with surgery.