Abstract
Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive tract in humans. The development of colorectal cancer is composed of multiple stages, starting with benign adenomatous polyps in the inner wall of the large intestine and rectum, and then gradually developing. Then it developed into advanced adenomas carcinoma in situ and invasive carcinoma. Represents the distant metastasis of the most advanced development. The purpose of this review is to novel routine screening and diagnostic methods (e.g., Endoscopy and CT colonoscopy, SEPT9 methylation assay, Fecal test) and find reliable molecular markers for early diagnosis of CRC.