Understanding the use of evidence in the WHO Classification of Tumours: a protocol for an evidence gap map of the classification of tumours of the lung

Abstract

IntroductionThere are gaps in the evidence base of tumour classification despite being essential for cancer diagnosis, treatment and patient care. The WHO in charge of the production of an updated international classification, the WHO Classification of Tumours (WCT), aims to adapt evidence gap map (EGM) methodology to inform future editions of the WCT, by providing a visual summary of the existing evidence.Methods and analysisBibliographical references used in the WCT fifth edition of Tumours of the Lung (Thoracic Tumours volume) will be used as search results of a literature search. A descriptive analysis of the cited evidence for tumour types and descriptors will be drafted and plotted in EPPI-Reviewer to develop a visual evidence map. The resulting EGM will reflect the number of cited studies in the size of the spheres, and the level of evidence by applying a four-colour code (red=low level evidence, orange=moderate level, green=high level and blue=unclassifiable). Overview of the findings will be provided in narrative form and a report will discuss the overall stage of cited research in the WCT and will include analysis of gaps, under-researched categories of tumour descriptors and pockets of low-level evidence.Ethics and disseminationNo ethics approval will be required as this is a study of previously published material. Findings of the EGM will be published and used to guide editors, stakeholders and researchers for future research planning and related decision-making, especially for the development of future editions of the WCT.PROSPERO registration numberCRD42022302327.

Mapping the cited evidence of ductal carcinoma in situ from the 5th edition of the World Health Organisation classification of tumours of the breast

“…With the first evidence map published in 2003 by Kaz et al, 9,37 it is now frequently implemented to guide decision-making in public health and social science as a rapid form of systematic review capable of handling large numbers of papers. 5 A systematic review by Miake-Lye et al 38 retrieved 39 published maps from 2003 to 2015, none of which were for pathology. The year 2022 saw the first efforts in evidence mapping in pathology by Del Aguila Mejıa et al, 5 who published a protocol to map the evidence in the 5th edition WCT of the Lung.…”

“…5 A systematic review by Miake-Lye et al 38 retrieved 39 published maps from 2003 to 2015, none of which were for pathology. The year 2022 saw the first efforts in evidence mapping in pathology by Del Aguila Mejıa et al, 5 who published a protocol to map the evidence in the 5th edition WCT of the Lung. Adapting its methodology, Md Nasir et al 24 mapped the evidence in the phyllodes tumour chapter of the WCT of the Breast.…”

“…To circumnavigate these challenges, the international WCT EVI Map project was launched, an essential part of which was the recent development of Hierarchy of Evidence for Tumour Pathology (HETP), aiming to augment the expert-led editorial process and to align it with evidence-based practice. 5,6 Currently, expert authors are responsible for choosing relevant literature to support their content. With an evidence-based system that includes the strength of the evidence, the subjectivity in study selection and interpretation can be reduced.…”

Phyllodes tumour evidence gaps mapped from the 5th edition of the WHO classification of tumours of the breast

“…We adopted a similar approach previously described by Del Aguila Mej ıa et al 18 in their EGM protocol to develop our PT EGM with slight modifications. Our framework was also based on the WCT structure of reporting tumour descriptors: localisation, clinical features, epidemiology, aetiology, pathogenesis, macroscopic appearance, histopathology, cytology, diagnostic molecular pathology, essential and desirable diagnostic criteria, staging, and prognosis and prediction.…”

“…We adopted a similar approach previously described by Del Aguila Mejía et al 18 . in their EGM protocol to develop our PT EGM with slight modifications.…”