Colorectal cancer (CRC) is the third most common cancer worldwide, the second deadliest cancer. It is reported that patients prefer non-invasive methods rather than invasive methods for the detection of CRC. Carcinoembryonic antigen (CEA) is commonly employed in clinical practice for early detection of CRC, but it is limited for its low sensitivity, which is around 30%-40%. DNA methylation is a commonly used biomarker for non-invasive tumor detection in plasma. We aim to develop and validate a methylation-based blood test for CRC based on genome-wide methylation detection. There are two steps. Firstly, this prospective, clinical study aims to establish the diagnostic model based on tumor-specific plasma ctDNA methylation markers. Secondly, this study is to compare the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of plasma circulating tumor DNA (ctDNA) methylation with CEA in detecting 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.