Assistant Professor Mayo Clinic Arizona Phoenix, Arizona, United States
Objective: The role of local therapy (surgery and/or radiation therapy) in the setting of relapsed disease for pediatric patients with soft tissue sarcoma and Ewing sarcoma remains unclear. The purpose of this study is to describe local therapy approaches in pediatric patients with relapsed soft tissue sarcoma and Ewing sarcoma at a single institution.
Methods: An IRB approved retrospective chart review was completed. Patients with relapsed soft tissue sarcoma and Ewing sarcoma seen at Phoenix Children’s Hospital from 2018-2024 were included in the analysis. Pertinent patient characteristics, tumor characteristics, and treatment data from initial diagnosis and time of relapse were extracted. Local therapy was defined as surgery and/or radiation therapy. Descriptive statistics were used to collate patient and treatment characteristics.
Results: 31 patients were included in the analysis. Median age of the cohort was 16.0 years at time of relapse (range: 2.0-25.6). 14 (45.2%) patients were treated for relapsed Ewing sarcoma, 12 (38.7%) for rhabdomyosarcoma, and 5 (16.1%) for non-rhabdomyosarcoma soft tissue sarcoma. Median time to relapse from initial diagnosis was 1.06 years (range: 0.1-15.1 years). 6 patients (19.4%) presented with local relapse, 21 patients (67.7%) with metastatic relapse, and 4 patients (12.9%) with local and metastatic relapse. The most common sites of metastatic relapse were bone (n=14, 45.2%) and pulmonary (n=6,19.4%). 24 patients (77.4%) received systemic therapy for their first or later relapses; the majority received cytotoxic chemotherapy, over immunotherapy or targeted agents. Local therapy was employed to treat relapse in 25 patients (80.6%). Of those 25 patients, 14 patients (56%) received radiation therapy alone, 2 patients (8%) underwent surgery alone, and 9 patients (36%) received both surgery and radiation therapy. 15 (60%) of patients were treated with palliative intent and 10 (40%) patients were treated with curative intent at first relapse. Median radiation therapy dose at first or later relapse was 3133 cGy (range: 800-5580). 4 patients treated with surgery underwent debulking procedures for acute neurological symptoms. Median progression free survival from time of first relapse was 94 days (range: 15 days-10.5 years). At last follow up, 12 patients in the cohort are alive.
Conclusion: Approximately 81% of pediatric patients with relapsed soft tissue sarcoma and Ewing sarcoma receive local therapy as a component of relapse treatment, suggesting a role for local therapy measures in pediatric patients with relapsed soft tissue sarcoma and Ewing sarcoma. Radiation therapy is more commonly employed, and most patients (60%) are treated with palliative approaches to alleviate symptoms of metastatic disease. This data will help inform local therapy guidelines for future prospective cooperative group studies in this population.
