Comparison Of KRAS Mutational Analysis Detected Between Plasma And Tissue In NSCLC

Objective: The aim of this study was to explore the mutant frequency of KRAS inChinese patients and value the clinical significance of plasma KRAS mutation as apredictive marker for EGFR-TKI resistance from comparing with tumor-based KRASmutation and valuing the correlation between KRAS ased KRAS mutation analysis whichis simpler, less suffering and cheaper than tumomutation and NSCLC patients’ clinicalcharacteristics, to develop a plasma-br-based method.Method: DNA was extracted from the plasma and matched tumor tissues in30NSCLC patients. KRAS mutations in codons12and13detected using mutant-enrichedPCR-RFLP analysis, were compared in plasma and matched tumor tissue respectively.Correlations were analyzed between KRAS mutation and NSCLC patients’ clinicalcharacteristics by SPSS16.0statistical software to evaluate the clinical significance.Result:(1) KRAS mutations in codons12and13was neither detected in tissuessamples (0/30) nor in plasma samples (0/30). The consistency of mutant frequency inplasma and tumor tissue was0(0/30).(2) KRAS mutations in codons12and13in4tumor tissues and matched plasmasample were randomLy confirmed by sequecing analysis, and the result showedconsistency of non-mutation.Conclusion:(1) There was a high consistency of KRAS mutations detectedbetween plasma and matched tumor tissues in NSCLC patients，and the resultsconfirmed by sequencing analysis showed consistency. KRAS mutant state in plasmacan be a predictive marker for EGFR-TKI treatment.(2) Mutant-enriched PCR-RFLP analysis used in our study to detect KRASmutation in plasma and matched tumor tissues was feasible, simpler, cheaper andaccurate. (3) The KRAS mutation frequency in NSCLC patients in our study wassignificantly different from that of Western patients and Asians in the previous report，but consistent with the individual small scale investigation report that no KRASmutations in codons12and13were found in their studies.