Researchers Establish Systematic Mapping from ICD-10 to ICCC-3 for Childhood Cancer

Researchers have established the first systematic reverse mapping framework to translate cancer registry records coded in the International Classification of Diseases, Tenth Revision (ICD-10) into the International Classification of Childhood Cancer, Third Edition (ICCC-3). While forward mapping rules from ICCC-3 and ICD-O to ICD-10 already existed, the absence of an established reverse mapping method has posed a significant challenge for estimating global childhood and adolescent cancer burdens and conducting cross-database comparisons, since large cancer registries primarily employ ICD-10 while pediatric oncology research relies on ICCC-3 as its benchmark.

To evaluate the mapping framework, the investigators utilized pediatric cancer incidence data from United States registries published in Cancer Incidence in Five Continents (CI5) Volume XII, which provides dual coding in both ICD-10 and ICCC-3. The study cohort comprised 77,236 pediatric cancer cases coded under ICD-10 and 77,152 cases coded under ICCC-3. The researchers carried out direct mapping to the 12 main diagnostic groups of the ICCC-3 system and developed an ICD-O-3-derived crosswalk table specifically for lymphoid and hematopoietic neoplasms.

The analysis revealed that mapping concordance varied considerably across different tumor groups. Near-unity concordance (concordance ratio, CR ≈ 1.00) was observed for retinoblastoma, brain and central nervous system tumors, renal tumors, and hepatic tumors. In contrast, over-mapping occurred for other epithelial neoplasms and melanomas (CR = 1.29), bone tumors (CR = 1.11), and leukemias (CR = 1.07). Several tumor categories experienced under-mapping, including neuroblastomas (CR = 0.67), germ cell tumors (CR = 0.74), soft tissue sarcomas (CR = 0.85), lymphomas (CR = 0.88), and unspecified malignant neoplasms (CR = 0.47).

The authors attributed the overall variation in mapping concordance to insufficient morphological detail available within ICD-10 codes. Although the research team generated an ICD-O-3-derived crosswalk table intended for potential subgroup classification of lymphoid and hematopoietic neoplasms, case-level subgroup mapping was not performed within this analysis.

Subject of Research: Pediatric cancer classification mapping from ICD-10 to ICCC-3

Article Title: Mapping ICD-10 to ICCC-3 for childhood cancer classification using cancer incidence in five continents (CI5) data

Article References: Liu, J., Sun, X., Sun, M., & Yang, H. (2026). Mapping ICD-10 to ICCC-3 for childhood cancer classification using cancer incidence in five continents (CI5) data. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07907-y

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07907-y

Keywords: childhood cancer, pediatric oncology, ICD-10, ICCC-3, cancer classification, cancer registries, disease burden, CI5, Mapping, childhood, cancer, classification