A high cancer index is a high concentration of tumor markers found during blood test. If a high tumor marker is found, it does not necessarily mean that the patient has malignant tumor, because in addition to a significant increase in tumor patients, some tumor markers may also be mildly increased in some normal people or when there is mild inflammation. Clinically, for malignant tumors of the digestive system, the commonly investigated tumor marker is carcinoembryonic antigen, and the concentration of carcinoembryonic antigen will be abnormally increased in patients with malignant tumors. However, in some normal people or people with chronic intestinal inflammation, the concentration of carcinoembryonic antigen may also be high. However, this indicator usually remains within a stable range for a long time, that is, there is no significant progressive increase. If there is a persistent increase, patients should be alert to whether it is a malignant tumor of the digestive system, and they need to undergo further examination, including gastroscopy, colonoscopy, etc.