Background
The WHO Classification of Tumours (WCT) provides a uniform, internationally accepted nomenclature and diagnostic criteria that underpin cancer diagnosis, treatment, and research worldwide. This standardisation is fundamental to global health equity. Recent advances, particularly in molecular pathology, genomics, and related technologies, have transformed tumour classification, enabling more precise disease stratification and personalised therapeutic approaches. However, many of these technologies remain inaccessible in resource-limited settings, posing challenges to equitable implementation.
 
Objectives
The WCT, 6th edition (WCT-6), aims to promote global equity while incorporating rapid scientific and technological advances into the tumour classification.
 
Methodology
Multiple measures were implemented during the editorial process of WCT-6 to balance scientific progress with global applicability. Standing editorial board members nominated by global scientific and academic organisations have varying subspecialty expertise and geographical distribution. Expert editorial boards and authorship groups for each volume comprise members from diverse geographical and institutional backgrounds, with the selection process supported by the Blue Books Expert Selection Tool (BBEST), based on subject-matter expertise and bibliometric indicators. Each expert editorial board includes representation from low- and middle-income countries (LMICs), and molecular genetics, while authors from regions with high disease prevalence or mortality were recruited to provide local expertise where relevant. Six thematic subcommittees, Genetics and Genomics, Computational Pathology, WCT/LMIC Liaison, Tumour Harmonisation, Imaging and Radiology, and Gray Zone and Rare Tumours, with global representation across diverse resource settings and areas of specialisation, were established to provide structured input to the expert editorial boards.
 
Results
Clear criteria for recognising new tumour entities have been defined by the subcommittees. Emphasis is placed on the continued central role of morphology, supplemented by immunohistochemistry and molecular techniques. A layered approach to diagnoses has been adopted utilising clearly defined essential and desirable diagnostic criteria as suggested by  the LMIC subcommittee.  Each volume includes a molecular genetics representative to ensure harmonization of molecular content across the series. Furthermore, the molecular genetics subcommittee has developed specific guidelines for integrating molecular information into WCT – 6. Initiatives such as the Evidence Gap Map project, which develops Evidence Gap Maps for different tumour types, continue to identify areas of limited evidence, often reflecting global research disparities. Accessibility is supported by enhanced digital resources, including whole-slide imaging, radiology libraries, and emerging AI tools. Online access to the bluebooks remains available at a concessional rate to subscribers from low resource settings.   Implementation of ICD-O-4 with expanded histology codes improves global comparability of epidemiological data.
 
Conclusion
WCT-6 harnesses global expertise to produce an evidence-based, current, and universally applicable tumour classification. In addressing scientific advancement alongside resource variability, it also serves as an advocate for strengthening diagnostic capacity worldwide.

Please note this abstract is targetted towards targeted towards the WCT symposium on ‘Classifying cancer, changing lives’.