For most people, cancer checkup is a new thing. The biggest difference between it and regular medical checkups is the examination equipment and items, and the candidate who interprets the examination report. For example, conventional medical checkups usually use X-ray chest film to screen for lung cancer, while cancer prevention checkups use low-dose CT, which is more conducive to detecting small early lesions. In terms of examination items, cancer prevention checkups are more targeted, such as carcinoembryonic antigen (CEA) for intestinal cancer and gastrointestinal endoscopy for digestive tract tumor risk. In addition, the cancer checkups are interpreted and analyzed by experienced oncologists, which is more conducive to uncovering traces of tumors. Firstly, people with high risk of various types of tumors, such as frequent exposure to carcinogenic substances, family history of disease, etc.; secondly, residents of areas with high incidence of tumors, such as lung cancer, which has the highest incidence rate in Shanghai; thirdly, people with bad habits such as smoking, drinking, excessive stress and fatigue, such as medical personnel, etc.; and finally, people in the age group with high incidence of tumors, i.e. over forty-five years old. In recent years, the incidence of tumor has become younger, and the phenomenon of “knowing tumor when you are fifty” is common, which should be prevented in advance.