Impact of Centres With Different Patient Volume on Diagnostic Process, Therapeutic Strategy and Outcome in Patients With Localised Rhabdomyosarcoma: A Report From the European paediatric Soft tissue sarcoma Study Group (EpSSG)

Introduction: We examined the impact of the treatment centre volumes (number of patients per centre) on the management and outcomes of rhabdomyosarcoma (RMS) patients enrolled. Methods: We analysed 1613 patients with localised RMS treated from 2005 to 2016 in 126 European centres classified as high-, medium-, or low-volume according to the number of patients enrolled in the RMS 2005 protocol coordinated by the European paediatric Soft tissue sarcoma Study Group (EpSSG). We evaluated diagnostic and treatment indicators, protocol adherence and survival outcomes. Result: Patients’ demographic and tumour characteristics were overall comparable across groups, though high-volume centres treated more patients with advanced disease. Diagnostic work-up largely adhered to protocol recommendations, with minor differences: high-volume centres showed greater adherence to central pathology review (77.7%) and molecular testing (76.2%), while medium-volume centres used ¹⁸FDG-PET/CT more frequently (39.7%). Risk group misclassification occurred in 4.5% of patients, more often in low-volume centres. Other treatment quality indicators, including surgical margins, chemotherapy adherence, radiotherapy administration, and participation in the randomised trials, were comparable among groups. Five-year event-free survival and overall survival did not differ significantly between groups, including high-risk subgroups. Conclusion: In the treatment of paediatric RMS, adherence to standardised treatment protocols ensures consistent outcomes across centres of varying volumes. Observed differences in specific diagnostic processes highlight the importance of fostering international collaboration and drawing on the expertise of high-volume centres to enhance the quality of care and outcomes for paediatric RMS patients. The adoption of a standardised international protocol would help standardise care and outcomes across Europe, thereby minimising geographical disparities and ensuring equitable access to high-quality treatment.