Abstract 5698: Next generation sequencing of circulating-free DNA from advanced non small cell lung cancer patients using Gene Reader®

Background: Stand alone tests such as PCR-derived techniques, FISH or IHC are usually employed to determine clinically relevant alterations in non-small cell lung cancer (NSCLC). However, they target single genes and proteins. Mutiplex techniques can reduce the turnaround time and quantity of sample in this setting, but require a careful validation. Methods: A total of 41 cfDNA samples from serum and plasma from advanced NSCLC p were analyzed with the Actionable Insights Tumor Panel, which covers mutations in 15 clinically relevant genes, using the Gene Reader platform (Qiagen). The samples had been previously genotyped for EGFR, KRAS and BRAF mutations by stand alone, PNA-Taqman assays. Paired biopsies were available in 37 cases. The remaining 4 corresponded to p.T790M-positive blood samples of p progressing to EGFR TKIs. Results: Of the 41 samples taken into the GeneReader workflow, some had a DNA input concentration below specifications, in spite of this limitation, good results were obtained. 14 mutations were fully concordant between tissue, Taqman and GeneReader and the four p.T790M mutations were concordant between Taqman and GeneReader. Five mutations present in tissue were detected by GeneReader and not by Taqman and 11 mutations detected by Taqman were below the 1% detection threshold of GeneReader. Finally, 12 mutations present in tissue were not detected in cfDNA by any of the assays. Concordance between the stand alone tests and the Gene Reader in cfDNA was 64%, raising to 84% if mutations Conclusions: Application of NGS to liquid biopsies is challenging and requires a careful validation. However, once fully validated, NGS will probably become the methodology of choice for cfDNA analysis in NSCLC patients at presentation and at progression. Citation Format: Clara Mayo de las Casas, Monica Garzon, Nuria Jordana Ariza, Ariadna Balada, Jordi Bertran-Alamillo, Beatriz Garcia, Sergio Villatoro, Erika Aldeguer, Sonia Rodriguez, Raquel Campos, Santiago Viteri Ramirez, Maria Gonzalez-Cao, Niki Karachaliou, Rafael Rosell Costa, Miguel Angel Molina-Vila. Next generation sequencing of circulating-free DNA from advanced non small cell lung cancer patients using Gene Reader® [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5698. doi:10.1158/1538-7445.AM2017-5698