Investigated The Detection Of KRAS, BRAF Gene Mutation In Lung Adenocarcinoma Tumor Tissue By SARMS-PCR

Background Approximately 1.2 million new cases of lung cancer are diagnosed worldwide each year,80 percent of the patients with non-small cell lung cancer (NSCLC), and most of them are diagnosed at the advanced stage and have a poor prognosis, although early detection and standard treatment have progressed. Last 20 years, the individual treatment methods to NSCLC were increased with the methods of targeted therapy. Epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase(ALK) are the representativeness of precision cancer treatment in NSCLC, which is related to tumorigenesis, development and invasion. EGFR gene mutations are associated with clinical response to gefitinib and erlotinib,small molecule tyrosine kinase inhibitors of EGFR. There was dissatisfaction to EGFR-TKI in some patients with EGFR mutation, because the existence with the KRAS and BRAF gene mutation from downstream signal of mitogen-activated protein kinase and extracellular signal regulated kinase. KRAS gene mutation is 20 to 30 per cent in patients with NSCLC(somker or adenocarcinoma patients) and is the most mutation in the path of EGFR signal. The new data indicated that it is the marker of poor prognosis in the patients with BRAF gene mutation,and also may induce the tolerance to EGFR-TKI. It means that we must consider the effect of KRAS and BRAF gene mutation,when we begin to treat the patients with EGFR mutation.Objective To investgate mutation specific primers double amplification real-time probe amplification block mutation system (sARMS-PCR) method to detect the mutation KRAS and BRAF in non-small cell lung cancer (NSCLC) specimens and the relationships between the clinical and pathological characteristics to KRAS and mutated BRAF gene mutations in patients with non-small cell lung cancer. To provide a basis for choosing precision molecular targeted therapy and Understanding of EGFR-TKI resistance.Methods Collected 89 cases of formalin-fixed paraffin-embedded tumor tissue specimens in NSCLC patients from Jan 2013 to Dec 2013, Used DNA isolation kit to extract DNA in FFPE, Used sARMS-PCR to simultaneously dect KRAS and BRAF gene mutation.ResultsThere were 21 patients with KRAS gene mutations from the 89 specimens of NSCLC patients detected by sARMS. The rates of mutation detection were achived to 23.6% (21/89), which distribution main in G12A, G12D with 6 cases and in G12C with 5 patients. Two patients had mutation at G12V in concomitance with G12C or G12D. One patient had mutation at G13D,but G12S mutation was not found. There was significantly higher mutation rate of KRAS gene in male (31.5%,17/54) than that in female(12.9%,4/31) (P=0.030). There was one patient with BRAF gene mutation from 89 specimens (1/89), which was point mutation at V600E in a female patient with mucinous adenocarcinoma. There was not found patient with double mutations for KRAS and BRAF gene.ConclusionUsing sARMS-PCR technology for patients with NSCLC histological specimens KRAS, mutated BRAF mutation detection, the method is conveniently, the detection of the advantages of stable and reliable;KRAS mutations have correlation with gender (p < 0.05);With age, clinical stage, clinical features such as smoking is no significant correlation (p> 0.05);BRAF gene mutation because of too few cases failed to observe and sex, age, smoking and staging of correlation. Is given priority to with early, We do not found double mutations for KRAS and BRAF gene simultaneously in same patient.