RT Journal Article SR Electronic T1 Idylla EGFR assay on extracted DNA: advantages, limits and place in molecular screening according to the latest guidelines for non-small-cell lung cancer (NSCLC) patients JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP jclinpath-2022-208325 DO 10.1136/jcp-2022-208325 A1 Emmanuel Khalifa A1 Caroline Chapusot A1 Benjamin Tournier A1 Julie Sentis A1 Estelle Marion A1 Alicia Remond A1 Manon Aubry A1 Célia Pioche A1 Anthony Bergeron A1 Charlotte Primois A1 Larry Blanchard A1 Alice Millière A1 Marlène Boucheix A1 Yannick Léger A1 Marine Bairrao A1 Véronique Brouste A1 Laurent Martin A1 Isabelle Soubeyran YR 2022 UL http://jcp.bmj.com/content/early/2022/07/11/jcp-2022-208325.abstract AB Aims Idylla epidermal growth factor receptor (EGFR) is a fast and fully automated mutation assay that is easy to implement. However, under the Biocartis-recommended technical conditions, tissue sections are directly introduced into the cartridge, at the risk of exhausting the tumour sample. In this study, we evaluate the performance of Idylla EGFR on extracted DNA and discuss its place within the global non-small-cell lung cancer (NSCLC) screening strategy.Methods 577 comparative tests between Idylla EGFR on extracted DNA and next-generation sequencing (NGS) were performed across two centres.Results Preanalytical thresholds were established (20% tumour cell content, 50 ng DNA input) and challenged prospectively in routine practice. 16.8% of samples referred for screening were considered non eligible for Idylla EGFR testing. Due to discordant by design cases, Idylla EGFR sensitivity was 86.9% for currently actionable EGFR mutations. Idylla EGFR specificity was 100% in first-line screening. NGS was always feasible on the same DNA.Conclusion Idylla EGFR on extracted DNA is feasible and enables tumour material to be saved compared with tissue section use. It is not necessary to replace the analytical thresholds of the Biocartis algorithm. Due to both the limits of the mutational repertoire and the high increase of targetable genes in NSCLC, the use of Idylla EGFR should be restricted to clinical emergency situations accompanied by NGS.All data relevant to the study are included in the article or uploaded as online supplemental information.