粪便DNA甲基化检测在结直肠癌筛查中的应用-内科学专业论文.docxVIP

广州医科大学硕士学位论文 广州医科大学硕士学位论文 粪便 DNA 甲基化检测在结直肠癌筛查中的应用 PAGE PAGE 10 Stool DNA methylation detection in the screening of colorectal cancer Postgraduate:Yue You Lin Supervisor:Prof.Nie Yu Qiang Background In recent years, the morbidity and mortality of colorectal cancer (CRC) has increased rapidly. and age at onset was significantly ahead of schedule. At the same time，the cost of curing CRC is raised. Because of the most of colorectal adenocarcinoma are derived from adenoma, which provide us enough time to make early diagnosis. The mortality of the later colorectal cancer is high, it is crucial to make early detection.There are many screening methods for colorectal cancer, such as serum tumor markers,fecal occult blood testing (FOBT), radiographic examination,colonoscopy. But because of poor sensitivity and specificity,or lack of patients compliance, or the high cost,even serious complications such as bleeding and perforation et al,So far no one is suitable for large-scale clinical screening. Fecal DNA testing has many advantages, such as safety, good patient compliance , high sensitivity and specificity. With the development of molecular biology technology and theory, it was proved that the methylation status of cancer suppressor gene promoter region was closely related to the occurrence and development of tumor. Previous research has shown promoter methylation status of MGMT and XAF1 gene was closely related to colorectal tumor progress. The occurrence and development of colorectal cancer is a cellular genetic disease which involves a series of gene, mang steps. Joint detection feces methylation of multiple genes so as to improve the sensitivity of CRC screening. Objective To explore the significance of detecting MGMT、XAF1 gene methylation status in stool samples from patients with normal controls and colorectal polyps and colorectal adenocarcinoma as a diagnostic tool for colorectal cancer by means of methylation specific polymerase chain reaction．And evaluated the f