Advancing cancer data collection: ICD-11 implementation in European oncology and cancer registries

The International Classification of Diseases (ICD) is a cornerstone in medical data standardisation worldwide. The newly released ICD-11, with its updated chapter on neoplasms, is expected to revolutionise cancer data collection, particularly in European healthcare system. However, significant challenges to implementation remain, especially when transitioning from ICD-10, which has long underpinned cancer registration. This study aimed to assess the feasibility of implementing ICD-11 in European cancer registries and healthcare system by examining its coding structure for neoplasms, particularly its ability to replace ICD-10 in existing cancer data collection processes.

The analysis focused on ICD-11 Chapter 2 "Neoplasms", including pre-coordination and post-coordination coding structures. A comprehensive mapping of ICD-10 to ICD-11 codes was performed for cancer site, morphology, grade, stage, laterality and prognostic factors. Additionally, tools for coding validation and their applications in registries and hospital IT systems were reviewed. Results were assessed for accuracy, consistency, and ease of implementation.

ICD-11 allows for more detailed coding of neoplasms, especially through post-coordination, which enhances precision in capturing tumour subtypes and prognostic factors. Nevertheless, inconsistencies were observed in grading and staging systems, allowing for invalid combinations. Mapping between ICD-10 and ICD-11 also revealed gaps, particularly in representing complex cancer diagnoses.

While ICD-11 presents advanced coding options for cancer data, its complexity and the lack of validation mechanisms present challenges for immediate use in cancer registries. The transition from ICD-10 will necessitate extensive training, improved mapping tools, and the introduction of validation systems to ensure accurate data collection. Cancer registries are well-suited to support this transition, but further refinements to ICD-11 are essential before full adoption.