Treatment of extracranial malignant rhabdoid tumors in children with surgery and or radiotherapy on a multiagent chemotherapy protocol- insights from a single centre cohort

INTRODUCTION: Extracranial malignant rhabdoid tumors (eMRTs) are rare childhood cancers with poor outcomes and no optimal therapeutic strategies. We report our experience in children with eMRT treated at a tertiary hospital in India. MATERIALS AND METHODS: Retrospective analyses of children (≤ 15 years) with pathologically confirmed eMRT, treated between January 2011 to June 2023, were performed. The staging was based on whole-body 18F-FDG PET/CT and brain MRI. Children treated with a curative intent received a multimodality protocol consisting of chemotherapy and local treatment at 10-12 weeks (surgery and/or radiotherapy). RESULTS: Ninety-six children with eMRT were registered during this period, with a median age of 18.5 months (IQR, 0.7-176 months). Thirty patients (31%) had renal MRT, and 66 (69%) had extrarenal MRT. Among the 73 patients with metastatic disease, only two patients proceeded with curative therapy after discussion with their families. At a median follow-up of 12 months (range, 2-64 months), the 2-year EFS and OS of the treated patients (n = 25, Stage I/II-12, III/IV-13) were 37.1% (SE ± 10%) and 45% (SE ± 11.2%), respectively. The application of surgery and radiotherapy alone had prognostic significance for EFS and OS, with the best outcomes for those who received both (p = 0.02). CONCLUSION: Extracranial MRT is a highly aggressive tumor in young children with very poor outcomes. Incorporating both surgical resection and radiotherapy into local treatment, where feasible, may improve patient outcomes.