Short report: Performance evaluation of the Idylla\u2122 KRAS and EGFR mutation tests on paraffin-embedded\xa0cytological NSCLC samples

Saskia Offerman,Clemens F Prinsen,Jeanette Kamphorst,Ageeth Knol,Maarten Niemantsverdriet,Natalie Methorst

doi:10.1186/s13000-021-01121-3

Saskia Offerman, Clemens F Prinsen + Show 4 more

Open Access

https://doi.org/10.1186/s13000-021-01121-3

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Journal: Diagnostic Pathology	Publication Date: Aug 3, 2021
Citations: 3	License type: open-access

Affiliation: Isala, Canisius-Wilhelmina Ziekenhuis

Abstract

BackgroundQuick and reliable testing of EGFR and KRAS is needed in non-small cell lung cancer (NSCLC) to ensure optimal decision-making for targeted therapy. The Idylla™ platform was designed for Formalin-Fixed Paraffin-Embedded (FFPE) tissue sections but recently several studies were published that evaluated its potential for cytological specimens. This study aimed to validate the Idylla™ platform for the detection of EGFR/KRAS mutations in cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding.Material and methodsThe KRAS Idylla™ test were performed on 11 specimens with a known KRAS mutation. The EGFR Idylla™ test was performed on 18 specimens with a known primary EGFR mutation and 7 specimens with a primary EGFR-EGFR T790M resistance mutation combination.ResultsConcordant KRAS and primary EGFR mutations were detected for both KRAS and primary EGFR mutations. Samples with a total CQ value of < 26 could be considered negative. Samples with a total CQ value of > 26 could not be assessed (probability of false-negative). In specimens with a primary EGFR-EGFR T790M resistance mutation combination, 5/7 cases were not concordant.ConclusionOur results confirm the conclusion of recent reports that the Idylla™EGFR assay is not suitable in a resistance to EGFR TKI setting, also not in our cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. KRAS and primary EGFR mutations were detected using the Idylla™ assays in virtually all cytological NSCLC samples. This analysis was rapid and time-saving compared to other mutation detection assays and may be useful if the amount of material is insufficient to perform a full set of molecular tests.

Highlights

Eligibility for targeted therapy with specific Tyrosine Kinase Inhibitors (TKI’s) for non-Small Cell Lung Cancer (NSCLC) is assessed by analysis of tumor tissue of either the primary tumor or mediastinal lymph node metastasis for specific mutations [1,2,3]
Concordant KRAS and primary EGFR mutations were detected for both KRAS and primary EGFR mutations
Our results confirm the conclusion of recent reports that the IdyllaTMEGFR assay is not suitable in a resistance to EGFR TKI setting, not in our cytological non-small cell lung cancer (NSCLC) samples prepared as cytoblocks using AGAR and paraffin embedding

Summary

Introduction

Eligibility for targeted therapy with specific Tyrosine Kinase Inhibitors (TKI’s) for non-Small Cell Lung Cancer (NSCLC) is assessed by analysis of tumor tissue of either the primary tumor or mediastinal lymph node metastasis for specific mutations [1,2,3]. In patients with advanced or metastatic NSCLC targeted treatment with first or second- generation EGFR TKI’s can be given after detection of activating EGFR mutations [1,2,3]. KRAS activating mutations are found in 25–30% of non-small cell lung cancer (NSCLC) samples and these samples rarely harbor other targetable driver mutations [1]. Quick and reliable testing of EGFR and KRAS is needed in non-small cell lung cancer (NSCLC) to ensure optimal decision-making for targeted therapy. This study aimed to validate the IdyllaTM platform for the detection of EGFR/KRAS mutations in cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding

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