Current management of pulmonary relapse in Ewing sarcoma: A report from the Pediatric Surgical Oncology Research Collaborative

Background: Relapse occurs in 30–40 % of patients with localized Ewing sarcoma (EWS). Our objective was to describe the current management and outcomes of patients with initially localized EWS who experience first pulmonary relapse. Methods: This multi-center retrospective cohort study included patients ≤22 years old with initially localized EWS treated from 2007 to 2020 at 19 Pediatric Surgical Oncology Research Collaborative institutions, who developed pulmonary relapse. Kaplan-Meier analysis was performed. Results: Thirty-three patients with initially localized EWS developed pulmonary relapse at a median age of 17 (IQR 14; 20) years. Eleven (33 %) patients also had extra-pulmonary metastases (EPM) at relapse. Among the 22 (67 %) patients with pulmonary-only relapse, 10 (45 %) had solitary pulmonary nodules. Pulmonary metastasectomy was performed in 8/10 (80 %) patients with solitary pulmonary-only metastases, 5/12 (42 %) patients with multiple pulmonary-only metastases, and 2/11 (18 %) patients who also had EPM. Whole lung irradiation was administered in 7/10 (70 %) with solitary pulmonary-only metastases, 7/12 (58 %) with multiple pulmonary-only metastases, and 2/11 (18 %) with EPM. Rates of further pulmonary relapse/progression were similar between groups (p = 0.97). In Kaplan-Meier analysis, 3-year overall survival was 73 % with solitary pulmonary-only metastases, 40 % with multiple pulmonary-only metastases, and 23 % with EPM (p = 0.097). Conclusions: While survival for patients with relapsed EWS is poor, the subset of patients with solitary relapse confined to the lung are often good candidates for pulmonary metastasectomy and have a non-statistically significant trend towards improved survival outcomes.