The Global Landscape of Very Rare Tumors (VRT) in Pediatrics

Pediatric cancers are, by their nature, uncommon — yet within this already rare disease space lies a subset of tumors so infrequent that they present some of the most formidable diagnostic, therapeutic, and research challenges in oncology. Very rare tumors (VRTs) in children and adolescents, broadly defined by their exceptionally low incidence, span a diverse range of histologies, anatomical sites, and molecular profiles. Despite their individual rarity, collectively they represent a significant and underserved clinical burden across pediatric oncology centers worldwide.The global landscape of pediatric VRTs is shaped by a complex interplay of factors: limited prospective clinical trial data, small and geographically dispersed patient populations, diagnostic uncertainty, and marked disparities in access to specialized care. In high-income settings, advances in genomic profiling, precision medicine, and international collaborative networks have begun to shed light on the biological underpinnings of these tumors. Yet in low- and middle-income countries, the challenges are compounded by delays in diagnosis, restricted access to molecular testing, and a lack of standardized treatment protocols — leaving a substantial proportion of affected children without optimal care.Addressing these gaps requires a coordinated, multidisciplinary, and truly global effort. International registries, cross-institutional biobanking, multicentric collaborative molecular tumor boards, and collaborative research consortia are proving essential in accumulating the critical mass of cases necessary to generate meaningful evidence. At the same time, advances in next-generation sequencing, multi-omic profiling, and rare tumor-specific preclinical models are opening new avenues for understanding tumor biology and identifying actionable targets.This Research Topic seeks to bring together research that collectively advances our understanding of pediatric VRTs across their full spectrum — from molecular characterization and novel therapeutic strategies to epidemiological analyses, global health perspectives, and models of international collaboration. Contributions that illuminate geographic and demographic variation in incidence, outcomes, and access to care are particularly encouraged, as are studies leveraging registry data or multi-center cohorts to overcome the inherent limitations of small sample sizes.By fostering a global exchange of knowledge, this collection aims to accelerate progress in a field where individual institutional experience is rarely sufficient, and where international solidarity is not just beneficial — it is essential to improving outcomes for some of the most vulnerable and underserved patients in oncology.This Research Topic has aligned its definition of Rare Pediatric Tumors in accordance with the Joint Action on Rare Cancers in their paper, “Defining and listing very rare cancers of pediatric age: consensus of the Joint Action on Rare Cancers in cooperation with the European Cooperative Study Group for Pediatric Rare Tumors.”Please note: Manuscripts consisting solely of bioinformatics, computational analysis, or predictions of public databases which are not accompanied by validation (independent clinical or patient cohort, or biological validation in vitro or in vivo, which are not based on public databases) are not suitable for publication in this journal. Topic editors: Milena Villarroel, Maite Gorostegui, Ricardo Lopez-Almaraz, KARLA RODRIGUES Source: https://www.frontiersin.org/research-topics/81673/the-global-landscape-of-very-rare-tumors-vrt-in-pediatrics