Evaluation of the Prognostic Value of Low-Frequency KRAS Mutation Detection in Circulating Tumor DNA of Patients with Metastatic Colorectal Cancer

KRAS mutation in tumor tissue is a well-known predictor of resistance to the treatment anti-EGFR antibodies metastatic colorectal cancers (mCRC). However, prognostic value low-frequency plasma circulating DNA (ctDNA) predicting pretreated mCRC patients remains controversial. This study retrospectively reviewed clinical course, including response and anti-VEGF therapies, changes serum marker levels along with image studies <1.5% mutations detected ctDNA by next-generation sequencing (NGS) at single center Taiwan. We identified six G12V/G12D/G12S/G13D (variant allele frequency 0.26~1.23%) ctDNA. Co-occurring APC, TP53, MAP2K1, KEAP1, or CTNNB1 were also detected. Although all had adjustments within one month after genetic test, image-evident progression was noted median 4 months afterwards. Re-challenge therapy combination anti-EGFR, anti-VEGF, FOLFIRI chemotherapy found be ineffective patient 0.38% G12D baseline Our suggests that detection could used as patients.