Intermediate Risk Rhabdomyosarcoma in Very Young Children (Less Than or Equal to 24 Months) Treated on the Prior Children’s Oncology Group Protocol ARST1431

Winsnes K, Bradley JA, Gao Z, Gupta AA, Rothstein DH, Shenoy A, Venkatramani R, Xue W, Arndt C. Intermediate Risk Rhabdomyosarcoma in Very Young Children (Less Than or Equal to 24 Months) Treated on the Prior Children’s Oncology Group Protocol ARST1431. Pediatr Blood Cancer. 2026 Jun;73(6):e70293. doi: 10.1002/1545-5017.70293. Epub 2026 Mar 31. PMID: 41914453; PMCID: PMC13100859.

Rhabdomyosarcoma is the most common soft tissue sarcoma in pediatrics and infants are reported to have inferior outcomes. ARST1431 recommended delayed primary excision (DPE) while discouraging radiation (RT) deviations. This analysis compared outcomes among very young and older patients in this study. Demographic and tumor characteristics were summarized using frequencies and percentages. Local failure (LF) frequency was summarized by age group, RT and DPE status. Event-free survival (EFS) and overall survival (OS) were estimated using the Kaplan–Meier method and compared between age groups using the log-rank test.