Analysis Ofkrasmutations In Circulating Tumor Dna And Colorectal Cancer Tissue

The mutation status ofKRASis important for anti-EGFR therapy in colorectal cancer (CRC) patients; however, detection ofKRASmutations in circulating tumor DNA (ctDNA) is problematic. We investigated tissue and plasma assays forKRASmutations in CRC patients. TheKRASstatus of 407 CRC patients was evaluated using integration of amplification refractory mutation system polymerase chain reaction (PCR), melting curves and wild type DNA blocking (IAMB) in tissue and plasma samples. Disparate cases were re-evaluated by Sanger sequencing of tissue samples. General characteristics and tumor biomarkers including CEA, CA19-9 and CA125 were characterized. The prevalence ofKRASmutations was 40.8% in plasma and 49.1% in tissue. The overall percent agreement, positive percent agreement and negative percent agreement were 82.3, 76.3 and 90.8%, respectively. Older patients and higher TNM stage exhibited increased sensitivity for detectingKRASmutations in plasma. We found 54.1% of patients withKRASmutations using parallel analysis of tissue and plasma; only 36.4% of patients were detected by series analysis. We found that plasma basedKRASdetection with IAMB technology is an alternative to tissue basedKRAStesting.KRASmutations can be identified more easily when both assays are used together