Treatment results of childhood Ewing's sarcoma of the bone in Serbia

The purpose of this study was to present treatment results of childhood Ewing's sarcoma (ES) of the bone in Serbia and to analyze prognostic factors.We performed a detailed analysis on a series of 107 patients with ES of the bone treated at the Institute for Oncology and Radiology of Serbia between 2000 and 2014, using modern multimodal therapy.Median age at the time of diagnosis was 14 years, with 56.07% of the patients being ≤14 years. There was a male predominance (59.81%). The most common primary sites were pelvis (25.23%), femur (17.76%) and tibia (12.15%). Thirty-four patients (31.78%) had metastatic disease, 17 of which had isolated lung metastases, 9 bone metastases and 8 patients had both. Tumor size ≤ 8 cm had 38.32% and8 cm had 61.68% patients. Overall, 51.4% patients underwent surgery and radiotherapy as a local treatment modality after neoadjuvant chemotherapy. Radiotherapy alone was performed in 24 patients. The 5-year overall survival (OS) was 43.8%. For patients with localized disease, the 5-year OS was 56.4% and for patients with metastatic disease 17.6%. In patients with initially nonmetastatic disease, age under 14 years, with tumor size8 cm and a good response to the neoadjuvant chemotherapy, the OS correlated with better outcome.Modern multidisciplinary approach in treatment of childhood ES of the bone in accordance with the recommended pediatric protocols, gives good treatment results. Therapy should be performed in referral centers.