The Analysis Of Gene Mutation In Gastrointestinal Stromal Tumors And The Exploratory Study Of CtDNA In Peripheral Blood

Objective:Analysising the gene mutation in gastrointestinal stromal tumors, to investigate the relationship between the common mutation types and the primary tumor location; Detecting the circulating tumor DNA in peripheral blood of patients with gastrointestinal stromal tumor, and carries on the quantitative analysis.Methods:The gene mutation and its pathological characteristics of 70 patients with gastrointestinal stromal tumor who were diagnosed and treated in the General Hospital of PLA from September 2014 to December 2015 were retrospectively analyzed. Analysis of the common types of gene mutations in gastrointestinal stromal tumors and its relationship with tumor location, tumor size and mitotic figure, Using the Next Generation Sequencing to detect the ctDNA in peripheral blood of 13 patients with gastrointestinal stromal tumors diagnosed and treated in our hospital, and carries on the quantitative analysis;Discussing the content of ctDNA in peripheral blood of GIST was related to the tumor location, NIH risk classification and Whether the body is associated with tumor and other factors., Using SPSS20.0 statistical software to analyze the statistical indicators, count data using X2.Results:The ratio of male to female was 1.8:1 in the patients with gastrointestinal stromal tumors, Average age of 54.3 years, The incidence of stomach in 34 cases (48.6%),6 cases of duodenum (8.6%), small intestine (27.1%),2 cases (2.9%) of colon, 3 cases (4.3%), and other 6 cases (8.6%). NIH classification:high risk in 45 cases (64.3%), Intermediate 21 cases (30%), low risk in 3 cases (4.3%), very low risk in 1 cases (1.4%).The total mutation rate of C-KIT was 87.1%, the PDGFRA was 5.7%, and the WT-GIST was 7.2%. The constitutive factors of C-KIT gene mutation in exon 11,9,13 were statistically significant (P<0.05). the composition of the tumor location of exon 11 mutations was statistically significant (P<0.05), There was no significant correlation between the type of gene mutation and tumor size, mitotic figures.All the 13 patients with gastrointestinal stromal tumors. Peripheral blood was detected in 10 cases of patients with ctDNA,3 cases were negative. High risk patients were detected in 7 patients,3 cases were detected in the middle risk patients. The copy number of ctDNA in 2ml plasma was 0-106.7, The copy number of more than 5 in 3 cases, The copy number of more than 20 in 2 cases. The amount of ctDNA in the peripheral blood of patients in high risk group was higher than that in the middle risk group, The content of ctDNA in peripheral blood of patients with liver metastasis was higher than that in patients without liver metastasis.Conclusion:The primary mutation is found in exon 11, Exon 11 missense mutations in the most common type of mutations,tumor site is common in the stomach and small intestine; there is a correlation between gene mutations and tumor primary site; and there was no significant correlation between tumor size and mitotic figures. Gastrointestinal stromal tumors can be detected in peripheral blood ctDNA. and quantitative analysis can be carried out. Tumor location, NIH risk classification, disease status and other factors were the influence factors of ctDNA in peripheral blood.