Concordance between Comprehensive Cancer Genome Profiling in Plasma and Tumor Specimens

Abstract

IntroductionDetection of somatic genomic alterations in the plasma of patients with cancer (“liquid biopsy”) are increasingly being used in the clinic. However, the concordance of alterations identified in liquid biopsies with those detected in cancer specimens is not routinely being determined. MethodsWe sought to systematically compare alterations found by a massively parallel sequencing liquid biopsy assay covering 39 genes (NEOliquid [NEO New Oncology GmbH, Köln, Germany]) with those identified through routine diagnostic testing in a certified central pathology laboratory in a cohort of patients with nonsquamous NSCLC. NEOliquid is based on enrichment of the genomic territory of interest by hybrid capture and is thus capable of detecting point mutations, small insertions and deletions, copy number alterations, and gene rearrangements/fusions in a single assay. ResultsIn a cohort of 82 patients with matched blood/tissue samples, the concordance between NEOliquid and tissue-based routine testing was 98%, the sensitivity of NEOliquid was higher than 70%, and the specificity was 100%. Discordant cases included those with insufficient amounts of circulaating tumor DNA in plasma and cases in which known driver mutations (e.g., isocitrate dehydrogenase (NADP(+)), 1 systolic gene [IDH1] R132H, kinesin family member 5B gene [KIF5b–ret proto-oncogene [RET], or MNNG HOS Transforming gene [MET] exon 14) were found in the plasma but were not interrogated by routine tissue analyses. ConclusionsIn summary, NEOliquid offers accurate and reliable detection of clinically relevant driver alterations in plasma of patients with cancer.