Ewing's sarcoma family of tumors in adolescents in Beijing 2010-2019: a multicenter retrospective cohort study.

Background: Ewing's sarcoma family of tumors (ESFTs) comprises a group of aggressive malignancies predominantly affecting children and adolescents. This study aimed to evaluate the clinical characteristics, treatment outcomes, and prognostic factors in adolescent patients with ESFTs. Methods: A multicenter, retrospective cohort study was conducted on adolescents (aged 10-18 years) diagnosed with ESFTs between January 2010 and December 2019 across four major pediatric hospitals in Beijing, China. Results: A total of 79 patients were included. Primary tumors originated in bone in 75.9% of cases and in soft tissue in 24.1%, with metastases present at diagnosis in 31.6% of patients. The median tumor diameter was 5.8 cm for bone lesions and 8.0 cm for soft tissue lesions. Most patients (91.1%) received multimodal treatment. The 5-year overall survival (OS) and event-free survival rates were 64.5% and 59.0%, respectively. Univariate analysis identified several factors associated with poorer survival: tumor diameter exceeding 8 cm, trunk as the primary tumor site, absence of multimodal treatment, and initiation of local therapy more than 18 weeks after diagnosis. However, multivariate analysis revealed that metastatic disease at presentation was the only independent predictor of reduced OS. Conclusions: Metastasis is a prevalent and critical prognostic factor in adolescent ESFT patients. Multimodal treatment and timely initiation of local therapy may contribute to improved survival outcomes. These findings underscore the importance of early, comprehensive treatment strategies in managing ESFTs in adolescents.