It is possible to cure colon cancer in situ, which is the earliest stage of colon cancer in clinical staging, stage 0. It can be cured by surgical resection and does not require adjuvant treatment such as radiotherapy and chemotherapy after surgery. This kind of resection does not require open abdomen or laparoscopy, but complete resection can be achieved under colonoscopy, and the colonoscopy needs to be reviewed regularly after surgery. Because in situ cancer may reappear in other parts of the colon, especially when there is an intestinal adenoma, it is easy to develop cancer. Therefore, surgical resection is often required to try to remove the adenoma before it becomes cancerous, thus preventing the development of colon cancer.