Comparison of Diagnostic Sensitivity Between ctDNA Methylation and CEA in Colorectal Cancer

This is a comparative study. This study is to compare the diagnostic sensitivity between circulating tumor DNA methylation and carcinoembryonic antigen in detecting colorectal cancer. There are two steps in this study. Firstly, the diagnostic model is established based on tumor-specific plasma circulating tumor DNA methylation markers. Secondly, the sensitivity, specificity and accuracy of plasma circulating tumor DNA methylation are compared with that of carcinoembryonic antigen in detecting colorectal cancer.