Survival and Prognostic Factors in Ewing Sarcoma: Evaluating the Role of Radiotherapy in Multimodality Management

Abstract

Background: Ewing sarcoma is an aggressive small round blue cell malignancy that predominantly affects children and young adults. Radiotherapy plays a central role in local control, particularly in anatomically complex or unresectable disease. Methods: A retrospective cohort study of 51 patients with histologically confirmed Ewing sarcoma treated between January 2022 and December 2024 at a tertiary care centre was conducted. All patients received multi-agent chemotherapy, and radiotherapy was delivered with curative (adjuvant or definitive) or palliative intent. Advanced conformal techniques, including volumetric modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3DCRT), were used according to clinical indication. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan–Meier method. DFS was defined as the time from completion of primary treatment to recurrence or last follow-up. Prognostic factors were explored using univariate Cox proportional hazards regression. Results: The median age was 21 years (IQR 14.5–28.0), and 43.1% of patients were in the  paediatric age group. Metastatic disease at diagnosis was present in 27.5% of patients. Radiotherapy was delivered using conformal techniques in 68.6% of cases, most commonly VMAT. The median radiotherapy dose was 45 Gy. With a median follow-up of 28 months, the median OS and DFS were both 25 months. The 2-year OS rate was 75%. Higher radiotherapy dose and use of advanced conformal techniques were associated with improved survival outcomes in univariate analyses. No grade ≥3 acute toxicities were observed. Conclusion: Radiotherapy contributes significantly to local control and survival in Ewing sarcoma within a multimodality treatment framework. Metastatic disease at diagnosis remains the dominant adverse prognostic factor. Optimisation of local therapy through appropriate dose and modern conformal techniques may improve outcomes; however, larger prospective studies are required to validate these associations.