NCI's childhood cancer data initiative: Advancing pediatric cancer research

The Childhood Cancer Data Initiative (CCDI) is a transformative effort to accelerate research and improve outcomes for children, adolescents, and young adults (AYAs) with cancer. Data are the cornerstone of cancer research, and CCDI is building a FAIR-aligned data ecosystem that functions as a multi-stakeholder interoperability platform, integrating diverse tools and services to advance pediatric cancer research. All CCDI tools and resources are accessible through the CCDI Hub, the central entry point to the ecosystem. The foundation begins with the CCDI data model, which establishes harmonized data standards to ensure consistency and interoperability across data sets, offering a framework for discovery and analysis. Building Cohorts: The CCDI Childhood Cancer Data Catalog serves as a comprehensive inventory of pediatric and AYA cancer data resources, including registries, repositories, knowledgebases, and catalogs. It provides study-level summaries and helps users identify where specific data types and studies are located. Once users identify studies of interest, they can move to the CCDI Hub Explore Dashboard to search CCDI data sets. The dashboard indexes data at the file level to facilitate cohort building. Users can build cohorts within the Childhood Cancer Data Commons (C3DC) using clinical data, or within the National Childhood Cancer Registry (NCCR) using real-world data. Cohorts built in C3DC can be exported as manifests containing participant identifiers, which can then be uploaded to the CCDI Hub to locate associated genomic, imaging, or other data. Similarly, users can export cohorts to NCCR to access related real-world data. For cross-institutional discovery, users can query pediatric data sets across participating repositories using the CCDI Federation API, as if querying a single virtual database.All of these resources are interconnected through the CCDI Participant Index, which maps participant identifiers across studies and repositories and allows researchers to connect data from the same participant, supporting data integration and cohort expansion. Analysis and Visualization: After cohorts are built, researchers can leverage integrated analysis and visualization platforms to further explore, interpret, and derive insights from the data. The Cancer Genomics Cloud provides a cloud-based computational environment where researchers can analyze data using custom workflows and advanced analytical tools. To make data accessible to clinicians and non-bioinformaticians, CCDI offers intuitive visualization platforms like the CCDI cBioPortal Cancer Data Explorer. Together, CCDI's many tools and resources, integrating data from thousands of participants, enable new insights that would not be possible when studied in isolation.