Mapping the Evidence for the WHO Classification of Tumours: a Living Evidence Gap Map by Tumour Type.

The WHO Classification of Tumours (WCT) underpins cancer diagnosis, and hence treatment and care of cancer patients, as well as research into cancer epidemiology, prevention, diagnosis, and treatment. However, decisions for such a global reference tool are not always informed by the best available evidence, and risks of incorporating misinformation into the clinical decisions pathway exist. We aim to develop a tool that maps existing evidence, showing gaps, identifying pockets of low-level evidence, and synthesis of reliable evidence. The tool will map the evidence base of the WCT in order to facilitate evidence-based decision-making in pathology, and promote the application of higher research standards in the field. We will adapt the recently developed Evidence Gap Map (EGM) methodology, first time ever to be used in biomedicine. The resulting EGMs will increase the discoverability and use of studies by the WCT decision-makers, research commissioners, researchers and others. Our WCT-EVI-MAP project is organized in three subsequent phases, where we will apply a stepwise approach to: first, develop a framework and define evidence levels based on expert consensus; second, elaborate a series of Megamaps in iterative cycles describing evidence of all tumour types; third, perform a descriptive analysis of the use of evidence in a continuous updated exercise. To overcome identified challenges, several strategies are proposed, such as using recent advances in technologies, following a strict multidisciplinary approach and integrating this project into the WCT strategic planning for the 6th edition. We believe that the WCT EVI-MAP will represent a ground-breaking advance for the WCT and research in the field, and will accelerate progress in cancer diagnosis and management. Integration of evidence-based medicine methods has been shown to have a positive impact in other specialized medical fields and our project represents a first step towards an evidence-based pathology.