Background: The World Health Organization (WHO) Classification of Tumours (WCT), published as the WHO Blue Books and the Blue Books online, is the ‘gold standard’ used by pathologists, clinicians and researchers for cancer diagnosis, research, treatment and prognosis. It encompasses scientific consensus of global experts to define all tumour types and their characteristics, acknowledging the multidimensional nature of cancer including histopathology but also newer insights from molecular biology, genetics or radiology, among others. Decision-making in pathology has historically been consensus based. The hierarchy of evidence that applies to questions of clinical effectiveness is less relevant in pathology. This project signifies a major shift to moving the practice of pathology from consensus-based to evidence-based practice.
Objectives: The WCT EVI MAP project (funded by the European Commission) is using Evidence Gap Map (EGM) methodology to systematically map the evidence landscape relevant to tumour classification and diagnosis, identifying pockets of low-level evidence or research gaps. This information will be publicly available through a living web tool allowing the WCT authors, pathologists, cancer researchers and stakeholders to readily access the existing evidence.
Methods: An EGM will be produced for all tumours by organ or place. The EGM framework has been defined in a stepwise process: first, we have undertaken a Delphi study to define a hierarchy of evidence for pathology; second, an advisory board comprising key stakeholders has defined the EGM framework; and third, the resulting framework has been piloted and modified accordingly. The EGMs will become available through a Mega map public tool. Rigorous and transparent methods have been used to locate and include evidence.
Conclusions: The WCT EVI MAP project will improve the quality of evidence available by making visible and transparent all the existing evidence used for classifying and defining tumours. A completed map, for lung tumours, will demonstrate the potential value of the EGMs. Once gaps and pockets of low-quality evidence are identified, research agencies play a crucial role in tailoring research to fill those gaps and strengthening the evidence base of cancer decision-making in pathology.
Patient, public and/or healthcare consumer involvement: In protocol design and framework development.