Plasma ctDNA RAS mutation analysis for the diagnosis and treatment monitoring of metastatic colorectal cancer patients

• DOI: 10.1093/annonc/mdx125
• Publication Date: 2017-04-07T19:11:18Z
• Authors: J. Vidal; L. Muinelo; A. Dalmases; F. Jones; D. Edelstein; M. Iglesias; M. Orrillo; A. Abalo; C. Rodríguez; E. Brozos; Y. Vidal; S. Candamio; F. Vázquez; J. Ruiz; M. Guix; L. Visa; V. Sikri; J. Albanell; B. Bellosillo; R. López; C. Montagut
• Keywords: Concordance; Panitumumab

BackgroundRAS assessment is mandatory for therapy decision in metastatic colorectal cancer (mCRC) patients. This determination based on tumor tissue, however, genotyping of circulating (ct)DNA offers clear advantages as a minimally invasive method that represents heterogeneity. Our study aims to evaluate the use ctDNA an alternative determining baseline RAS status and subsequent monitoring mutations during component routine clinical practice.Patients methodsRAS mutational plasma was evaluated mCRC patients by OncoBEAM™ CRC assay. Concordance results tissue retrospectively evaluated.RAS were also prospectively monitored longitudinal samples from selected patients.ResultsAnalysis 115 showed 93% overall agreement. Plasma/tissue discrepancies mainly explained spatial temporal Analysis clinico-pathological features site metastasis (i.e. peritoneal, lung), histology mucinous) administration treatment previous blood collection negatively impacted detection ctDNA. In with mutant tumors treated chemotherapy/antiangiogenic, analysis mirrored response treatment, being early predictor response. wt, revealed OncoBEAM useful detect emergence anti-EGFR treatment.ConclusionThe high agreement between supports blood-based testing viable practice. describes practical specifications optimize determination. Moreover, monitor undergoing systemic resistance efficacy particular treatments.