Prognostic factors and treatment outcomes of adult Ewing sarcoma from 20 years of experience in a specialized center

Objectives: The objective of the study is to describe the clinical features, treatment outcomes, and prognostic factors associated with Ewing sarcoma (ES) among adult Saudi patients. Methods: This retrospective study included 105 ES patients diagnosed at King Faisal Specialist Hospital and Research Center (1997–2016). Clinical data, including characteristics, treatment modalities, and outcomes, were collected using Research Electronic Data Capture. Chemotherapy response was assessed using Response Evaluation Criteria in Solid Tumors criteria. Survival was analyzed with Kaplan–Meier and Cox regression models. Statistical significance was set at P ≤ 0.05, using the Statistical Package for the Social Sciences Version 29. Results: The median age was 20 years (range 14–54); 65.7% were male. Common presentations included painful swelling (49.5%) and tumor site pain (21.9%). Most tumors were skeletal (70.5%), primarily in extremities (37.1%), pelvis (30.5%), and trunk (20%). At diagnosis, 62.9% (66) had localized disease, while 37.1% (39) presented with metastases. Localized disease treatment included neoadjuvant chemotherapy and locoregional therapy for 61 patients (92.4%): Surgery (19), radiation (26), and combination (16). Adjuvant chemotherapy was given to 33 patients, with 83.3% receiving vincristine, dactinomycin D, ifosfamide, and doxorubicin (VAIA) protocol (median 8 cycles, range 2–14). For metastatic disease, 37 patients received VAIA protocol (median 10 cycles). The median follow-up was 82 months. The median event-free survival (EFS) for localized disease was 31 months; median overall survival (OS) was not reached; 5-year OS was 68%. For metastatic disease, the median EFS and OS were 10 and 28 months. Poor performance status, metastasis, and elevated absolute neutrophil count, lactate dehydrogenase, and alkaline phosphatase levels were associated with worse survival outcomes. Conclusion: Despite advancements, challenges remain in managing ES and preventing relapse. Identifying prognostic factors is crucial for risk stratification and treatment decisions.