More than 75% of malignant tumors in the human body occur in parts of the body that are easy to detect and easy to find. Many kinds of tumors can be detected at an early stage through health examination, tumor screening and regular follow-up, such as cervical cancer, breast cancer, esophageal cancer, nasopharyngeal cancer, liver cancer, colorectal cancer, etc. In China, early detection and treatment of nasopharyngeal cancer, liver cancer and esophageal cancer have achieved good results. Among them, early detection and early treatment of nasopharyngeal cancer, liver cancer and esophageal cancer have achieved good results in China. At present, cervical cancer and breast cancer are the two malignant tumors for which WHO has actively recommended the implementation of census to all countries. The effective implementation of various preventive measures has led to an obvious increase in the early diagnosis rate of cancer, and the early diagnosis of nasopharyngeal carcinoma has increased from 20% to 30% to 80% to 90% by applying serologic screening since 1978. In recent years, mammography has received more and more attention, and the results of many overseas follow-up and control studies have shown that mammography screening can reduce the mortality rate of breast cancer in women over 50 years old by 20% to 43%. Seventy percent of intraductal carcinomas detected on screening were attributed to the detection of microcalcified foci on x-ray. Other data show a 69% reduction in cervical cancer mortality, a 35% reduction in nasopharyngeal cancer, and a 20% reduction in esophageal cancer in the 1990’s compared to the 1970’s, thanks in large part to early detection of cancer. Tumor development is a relatively long process, and early detection, early diagnosis and early treatment is the key to improve the cure rate and reduce the mortality rate of cancer. Taking cervical cancer as an example, the 5-year survival rate of cervical cancer in situ and stage I cervical cancer after comprehensive treatment is as high as 99.1%, while it is reported that the 5-year survival rate of stage III cervical cancer is only 40%, and the prognosis of cervical cancer that has already metastasized or recurred is even worse. For example, in breast cancer, 90% of stage I breast cancer can be cured, while the 5-year survival rate of stage II and III patients is only 70% or 40%. In addition, the 5-year survival rate of gastric cancer confined to the gastric mucous layer after surgical resection reaches 90.9%. The 5-year survival rate of early esophageal cancer is 90.3%. It is also reported that the 5-year survival rate of liver cancer can reach 60% after early detection. From these data, we can see that cancer is not so terrible, as long as it is detected at an early stage, the treatment effect is still good.