Seoul, Korea – Researchers from around the globe convened in Seoul in October 2025 for the annual meeting of the International Childhood Cancer Cohort Consortium (I4C), a collaborative effort focused on understanding the causes and prevention of childhood cancers. Hosted by the National Cancer Center (NCC) of Korea and organized by Professor Eunhee Ha and her team, the two-day symposium brought together experts to share findings and strategize future research directions in pediatric oncology.
The I4C, established in 2005, represents a significant undertaking in childhood cancer research, pooling data from large cohort studies across multiple countries. This international collaboration aims to overcome the limitations of individual studies, which often lack the statistical power to identify rare risk factors for childhood cancers. The meeting highlighted recent expansions of the consortium, with the inclusion of new birth cohorts from the Pacific and East Asian region, bolstering the I4C’s capacity for comprehensive analysis.
Expanding the I4C Network in East Asia and Beyond
More than 50 participants attended the meeting both in person and virtually, according to the Folkehelseinstituttet. Presentations showcased the integration of three new birth cohorts into the I4C network: the Korean Children’s Environmental Health Study (Ko-CHENS), the Guangzhou Cohort Study (BIGCS) in China, and the Generation Victoria (GenV) in Australia. Researchers also presented ongoing work from cohorts in Taiwan, Shanghai, and Singapore. Detailed exposure measurements from Ko-CHENS and the Japan Environment and Children’s Study (JECS) were shared, contributing to a growing understanding of environmental factors influencing childhood cancer risk. Terry Dwyer, a key figure in the I4C’s history, presented an overview of the consortium’s progress and the opportunities presented by these new collaborations.
The I4C’s scope is broadening to include cancers that manifest in adolescence and young adulthood, a recent development highlighted at the Seoul meeting. Presentations by Martha Linet and Ora Paltiel explored potential sub-projects to investigate the links between pre- and perinatal factors and cancers developing in these older age groups. Melissa Wake discussed the importance of incorporating relevant variables into cohort studies as participants age, ensuring long-term data quality and analytical power.
Federated Analysis and Data Sharing Challenges
Recognizing the legal and logistical challenges of centralizing sensitive data from multiple countries, the I4C is prioritizing federated analyses. This approach allows researchers to analyze data within each cohort’s secure environment, rather than transferring it to a single location. A pilot project, initiated by researchers at the US National Cancer Institute and utilizing data from the Norwegian Mother and Child Cohort Study (MoBa) and the Danish National Birth Cohort (DNBC), was presented as a model for this collaborative approach. The project involves sharing a synthetic dataset and analysis code with each cohort, followed by individual analyses and a final meta-analysis.
The meeting also included discussions on the development of the I4C website and strategies for securing future funding, essential for sustaining the consortium’s long-term research goals. The I4C, which currently comprises 10 cohort studies across 15 countries and over 390,000 mother-child pairs, as reported by the International Agency for Research on Cancer (IARC), continues to be a vital resource for advancing our understanding of childhood cancer etiology.
The I4C’s commitment to collaborative, international research offers a promising path toward identifying preventable risk factors and ultimately reducing the incidence of childhood cancers worldwide. The consortium’s focus on federated analysis addresses critical data privacy concerns even as enabling large-scale, impactful research. Future efforts will likely concentrate on expanding the network further and refining analytical methods to unlock the full potential of these valuable cohort studies.
What comes next for the I4C involves continued data analysis from the newly integrated cohorts and the refinement of federated analysis techniques. Researchers will also be focusing on securing funding to support ongoing projects and expand the consortium’s reach. Share your thoughts on the importance of international collaboration in cancer research in the comments below.
