Clinical Characteristics and Survival Outcomes in a Cohort of Pediatric Rhabdomyosarcoma Patients: The Impact of...

Background: Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma, with survival dependent on risk stratification and multimodal therapy. This single-center study explored the clinical characteristics, treatment outcomes and prognostic factors of pediatric RMS to optimize local management. Methods: Data of RMS patients treated at Shanghai Children's Hospital from 2011 to 2024 were analyzed to estimate event-free survival (EFS) and overall survival (OS), and factors associated with survival. Patients received the Rs-99 (pre-2019) regimen or a modified Rs-2018 (post-2019) regimen. Results: A total of 76 RMS patients were identified. The 5-year EFS and OS for the entire cohort were 71.1% (95% CI, 62.3% to 83.3%) and 72.4% (95% CI, 64.0% to 84.5%), respectively. No statistically significant differences were observed in EFS and OS between the Rs-2018 and Rs-99 regimens. Univariate survival analysis indicated that metastasis was associated with prognosis: the 5-year EFS and OS of patients with metastatic disease were 35.0% (95% CI, 18.3% to 57.6%) and 40.0% (95% CI, 27.3% to 75.3%), while both the 5-year EFS and OS of patients with localized disease reached 83.9% (95% CI, 69.3% to 93.6%). Primary tumor resection status was a key prognostic factor for patients with localized disease, with a 5-year EFS of 100% for R0 resection and 46.7% (95% CI, 25.2% to 74.0%) for R2 resection. For patients with localized disease, EFS was comparable between those who underwent delayed primary excision (DPE) and upfront resection. Conclusions: Outcomes for patients with metastatic RMS remain poor. For those with localized disease, primary tumor resection status correlates with improved EFS and OS; additionally, DPE represents a feasible therapeutic option for localized RMS involving complex anatomical sites.