PT  - JOURNAL ARTICLE
AU  - De Luca, Caterina
AU  - Conticelli, Floriana
AU  - Leone, Alvaro
AU  - Gragnano, Gianluca
AU  - Salatiello, Maria
AU  - Galasso, Pasqualina
AU  - Pisapia, Pasquale
AU  - Grillo, Lucia Rosalba
AU  - Iaccarino, Antonino
AU  - Vigliar, Elena
AU  - Bellevicine, Claudio
AU  - Malapelle, Umberto
AU  - Troncone, Giancarlo
TI  - Is the Idylla <em>EGFR</em> Mutation Assay feasible on archival stained cytological smears? A pilot study
AID  - 10.1136/jclinpath-2019-205863
DP  - 2019 Sep 01
TA  - Journal of Clinical Pathology
PG  - 609--614
VI  - 72
IP  - 9
4099  - http://jcp.bmj.com/content/72/9/609.short
4100  - http://jcp.bmj.com/content/72/9/609.full
SO  - J Clin Pathol2019 Sep 01; 72
AB  - Aim The rapid and fully automated Idylla EGFR Mutation Assay has been specifically designed to process formalin-fixed, paraffin-embedded sections without requiring preliminary DNA extraction. This study evaluates whether this approach can also process archival smears from patients with non–small cell lung cancer (NSCLC) by scraping the stained cellular material directly into the cartridge.Methods The study was divided into two parts. In the first part, we carried out Idylla EGFR Mutation Assay on archival stained smears from 39 patients with NSCLC. Among these, 14 cases harboured a mutation in either exon 19 (n=11) or exon 21 (n=3), previously detected on DNA extracts by fragment length and TaqMan assays. In the second part, we evaluated whether de-staining of the smears could reduce background fluorescence.Results The Idylla EGFR Mutation Assay confirmed the presence of EGFR mutation in 11 instances (78.6%). However, concordance was higher for exon 19 deletions (10/11) than for exon 21 p.L858R assessments. Raw data showed a high background fluorescence in channel 2, where the EGFR exon 21 p.L858R mutation was detected. This interference, due to dye residues from the original staining, was partially reduced by de-staining the cytological material.Conclusions Our data, although preliminary, show that the Idylla EGFR Mutation Assay can reliably process most archival smears without requiring preliminary DNA extraction. Results may be further improved by de-staining the cellular material before insertion into the cartridge.