EPID-22. CNS metastasis in the pediatric population: a systematic review

Abstract Brain metastases in children are rare but aggressive, typically arising from neuroblastoma (MYCN-amplified), sarcomas, and CNS tumors. Unlike in adults, these metastases show frequent leptomeningeal spread and distinct molecular profiles. Poor prognosis persists due to limited availability of CNS-penetrant therapies that are safe for developing brains. Advanced MRI and molecular diagnostics (e.g., CSF liquid biopsy) are becoming increasingly crucial for early detection. The aim of this study was to search the literature for epidemiological data regarding CNS metastases in children. METHODS Systematic review was conducted, analyzing 21 studies retrieved from PubMed/MEDLINE and Web of Science databases (2019-2024). The search employed the following keywords: “pediatric cancer”, “brain metastasis”, “pediatric brain metastasis”, and “CNS metastasis”. Included studies were published in English or Portuguese and comprised retrospective analyses, randomized trials, and multicenter studies. A total of 29 studies were excluded for not meeting the inclusion criteria. RESULTS Neuroblastoma frequently spreads to the brain and leptomeninges (MYCN-driven), while CNS tumors mainly show leptomeningeal spread. Key pathways (FAK, miR-144-3p) were identified. Advanced imaging (3D FLAIR MRI) enhanced detection, and surgery, radiosurgery, and TTFields demonstrated efficacy. These findings highlight the need for pediatric-specific management strategies. DISCUSSION Pediatric cancers show distinct metastatic patterns compared to adult tumors. While neuroblastoma often spreads to the CNS, pediatric CNS tumors rarely metastasize extracranially. Early detection remains challenging, especially for leptomeningeal disease, and requires advanced imaging. Surgery and radiosurgery show promise, but further research is needed to refine pediatric-specific treatments. CONCLUSION This review highlights the unique metastatic patterns of pediatric cancers, particularly neuroblastoma’s CNS spread and the rare occurrence of extracranial metastases in CNS tumors. Emerging molecular targets offer therapeutic promise. Future priorities include validating biomarkers, improving imaging techniques, and conducting pediatric-specific clinical trials. Optimal management requires a multidisciplinary approach combining surgery, radiation, and novel therapies to improve outcomes.