Comparison of BEAMing assays and competitive approaches in the detection of main alteration of RAS in circulating DNA of non small-cell lung cancer (NSCLC) and metastatic colon cancer. Manuscript 2016.

e23056Background: A number of RAS mutations confer resistance to anti-EGFR therapies routinely used in the treatment of colon cancer. The objective of this study was to evaluate the pertinence of analyzing circulating-free plasma DNA (cfDNA) as an indicator of the mutational status of a tumor, in order to use liquid biopsies instead of invasive and painful tumor biopsies during tumor progression. Methods: A cohort of 24 lung and 25 colon cancer patients was constituted in the Hospices Civils of Lyon. Liquid biopsy plasma samples were collected at diagnosis (colon cancer) and during tumor progression (lung cancer) for the purpose of the current study. KRAS and NRAS somatic alterations were quantified using three different technologies: the Droplet Digital polymerase chain reaction (ddPCR) from BioRad, the BEAMing Digital PCR from Sysmex Inostics, and the NGS NextSeq 500 by Illumina with the Accel-Amplicon 56G Oncology Panel from SWIFT BIOSCIENCES. Results: We observed a high level of sensitivity and specif...