Detection of Peripheral Blood SEPT9 Gene Methylation Combined With Glycoprotein Tumor Markers in Diagnosis of Colorectal Cancer / 胃肠病学

ABSTRACT

Background: SEPT9 gene methylation is a specific biomarker of colorectal cancer, and its peripheral blood expression level can assess the risk of colorectal cancer. Aims: To investigate the clinical significance of detection of peripheral blood SEPT9 gene methylation and glycoprotein tumor markers in the diagnosis of colorectal cancer. Methods: A total of 57 normal controls, 61 colorectal adenoma and 71 colorectal cancer patients from Dec. 2016 to Apr. 2017 at the First Affiliated Hospital of Soochow University were enrolled. The peripheral blood SEPT9 gene methylation was detected by PCR fluorescence probe method, and levels of tumor markers CEA, CA125, CA19-9, CA72-4 and CA211 were determined. ROC curve was used to analyze the diagnostic value of above-mentioned indices for colorectal cancer. Logistic regression equation was established and used to evaluate the diagnostic value of SEPT9 gene combined with CEA. Results: The positivity rates of SEPT9 gene methylation in normal control group, adenoma group and colorectal cancer group were 0, 6.6% and 52.1%, respectively. CEA level in colorectal cancer group was significantly higher than that in normal control group and adenoma group (P<0.05). ROC curve analysis showed that AUC of SEPT9, CEA, combination of the two indicators for the diagnosis of colorectal cancer were 0.817, 0.707 and 0.793, respectively. Logistic regression analysis showed that the OR of SEPT9 and CEA for the diagnosis of colorectal cancer were 1.394 (1.198-1.762) and 1.325 (0.997-1.622), respectively. Conclusions: The positivity rate of peripheral blood SEPT9 gene methylation is significantly increased with the progress of disease, and the diagnostic value for colorectal cancer is high. The combination of peripheral blood SEPT9 gene methylation and CEA is helpful for improving the early screening rate of colorectal cancer.