Clinical Value Of Detecting Serous Cell-free DNA Methylation Level By Liquid-chip In Qualitative Diagnosis And Prognosis Evaluation Of Intracranial Tumors

Objective Detect the global genetic methylation level of cell-free DNA in different kinds of intracranial-tumors by liquid-chip process,then analyze the detection results by reference to clinical data,and evaluate the clinic value of this detection technology for screening and diagnosis and prognosis in intracranial-tumors,to estimate its clinic utility.Methods We detected the Alu element methylation level in serum specimens from 165 patients with intracranial-tumors(109 gliomas with different pathological types,and 56 different kinds of benign intracranial-tumors),and 50 healthy controls by liquid-chip process,as a representative of the global genetic methylation level.And the same to 36 paired tumor tissue samples.Then analyzed the detection results by reference to clinical data of all these cases,and evaluate the clinic value of this detecting process.Results Median methylation levels of global Cf-DNA were 55.62%(interquartile range [IQR],49.98-63.1%),69.16%(IQR,65.14-70.88%)and 67.54%(IQR,65.25-71.37%)in serum specimens of glioma patients,benign tumor patients and healthy volunteers.Global genetic methylation level in gliomas was significantly lower than benign tumors and healthy controls(P<0.01),and the lower methylation level found expression in the more malignant gliomas.However,there are no significantly difference between benign tumor patients and healthy volunteers(P>0.05).In addition,the genetic methylation levels showed the significant concordance between serum and tumor specimens(Spearman r=0.7526),and the Overall Survival showed a positive correlation with genetic methylation level in glioma patients.41 different samples in duplicates could be analyzed in each experiment by this process.Conclusions Detecting the global genetic methylation level of Cf-DNA is of reference value for screening different types of intracranial-tumors,diagnosis and prognosis of malignant gliomas.On account of its characteristic advantages of non-invasive,simple,low-cost,high-through,accuracy,and the parallel detecting mode,the process that detecting biomarkers in Cf-DNA by liquid-chip system is supposed to widely utilize in diagnosis and prognosis of intracranial-tumors.