WS02.02 Pathology Section I: Synopsis EURACAN/IASLC

Abstract

Whilst molecular and immunologic breakthroughs have transformed the management of lung cancers, changes have not been as marked for malignant pleural mesothelioma. Therefore, in 2018, a multidisciplinary group (pathologists, molecular biologists, surgeons, radiologists and oncologists), sponsored by EURACAN/IASLC, met in order to critically review the current classification, in which pathologic diagnosis has hitherto been essentially limited to three histologic subtypes.1 Subsequent recommendations in relation to pathology classification were firstly to include architectural patterns, and stromal and cytologic features that refine prognostication. Second, subject to data accrual, malignant mesothelioma in situ could be an additional category. Third, grading of epithelioid MPMs should be routinely undertaken,2 Fourth, other prognostically relevant histologic characteristics should be routinely reported. Clinically relevant molecular data such as PD-L1, BAP1, CDKN2A) should be incorporated into reports, if undertaken and other molecular data accrued as part of future trials. Resection specimens (i.e. extended pleurectomy/decortication and extrapleural pneumonectomy) should be pathologically staged with smaller specimens being clinically staged. When surgical biopsies are taken, at least 3 separate areas should be sampled from the pleural cavity, if feasible. Image-acquisition protocols/imaging terminology should be standardized to aid research/refine clinical staging. Multidisciplinary tumor boards should include pathologists to ensure appropriate treatment options are considered and all histologic subtypes should be considered potential candidates for chemotherapy and first line clinical trials unless there is a compelling reason. REFERENCES 1. WHO Classification of Tumours of the Lung, Pleura, Thymus and Heart. Lyons, France.: International Agency for Research on Cancer (IARC); 2015. 2. Rosen LE, Karrison T, Ananthanarayanan V, et al. Nuclear grade and necrosis predict prognosis in malignant epithelioid pleural mesothelioma: a multi-institutional study. Mod Pathol 2018. multidiciplinary, Mesothelioma, classification