Ewing family tumors of the appendicular skeleton: a retrospective analysis of prognostic factors

Purpose: Authors retrospectively analyzed possible prognostic factors in a series of patients affected by Ewing sarcoma of extremities (eEWS) and treated over a 20-year period at a single institution. Methods: Between 1997 and 2017, 88 bone eEWS were treated at our institution. Staging, age, gender, tumoral volume, local treatment, surgical margins, post-ChT necrosis were investigated for prognostic correlation with overall survival (OS) and event-free survival (EFS). Median follow-up was 74 months (1–236). Results: Staging of disease correlated with OS (81% vs 59%, p = 0.01) and not with EFS (68% vs 57%, p = 0.28) in localized vs metastatic eEWS at presentation. Age ≥ 14 years (p = 0.002) and volume ≥ 100 cm3 (p = 0.04) were significant negative prognostic factors. No difference was found in local treatment: OS was 76% vs 63% (p = 0.33), while EFS was 68% vs 49% (p = 0.06) after surgery alone or surgery + radiotherapy, respectively. Regarding surgical margins, OS was 76% vs 38% (p = 0.14), and EFS was 65% vs 33% (p = 0.14) in adequate vs not adequate, respectively. OS was 86% and 68% in good and poor responders, respectively (p = 0.13). Conclusion: In eEWS, metastatic disease at presentation, age > 14 years and tumoral volume > 100 cm3 are negative prognostic factors. Intensified adjuvant ChT can improve prognosis in poor responders and metastatic patients.