The length of survival of cancer patients is closely related to the clinical stage, and the earlier the detection, the higher the chance of cure. The 5-year survival rate of several common cancers (nasopharyngeal cancer, cervical cancer, rectal cancer, breast cancer, etc.) can reach 70-95% if treated early, but the 5-year survival rate of late stage treatment is only 5-10%. Therefore, early detection and early treatment of cancer are very important. In the early stage of cancer, most of the cancer patients either do not feel any symptoms or have mild symptoms, which are easy to be ignored; when the disease progresses to the point of obvious symptoms and they have to seek medical attention, they often miss the best treatment time and need to take comprehensive treatment, which significantly increases the treatment cost, increases the treatment side effects, and the treatment effect is poor, and the 5-year survival rate decreases significantly. Nasopharyngeal cancer is one of the most common malignant tumors in China. Stage I nasopharyngeal cancer requires only radiotherapy alone, and the 5-year survival rate can reach more than 80%, while the chance of damage to surrounding important organs (such as eyes, brainstem, spinal cord, etc.) is small, and the total treatment cost is not high. For example, a patient with early-stage nasopharyngeal carcinoma from a mountain village had radiotherapy in our hospital more than 30 years ago and has survived for a long time after radiotherapy. In contrast, nasopharyngeal carcinoma in stage III-IVa requires combined radiotherapy and chemotherapy, the total dose of radiotherapy increases, the number of radiotherapy sessions increases, and the scope of irradiation expands, with significantly more toxic side effects. Especially for some local very advanced nasopharyngeal cancers, such as invasion of one side of the orbit, in order to achieve a better control rate, there is an unavoidable risk of blindness in one eye or even both eyes, and a heavy price to pay after treatment, while the chance of recurrence also increases significantly, and medical costs also rise dramatically. Patients with advanced cancer are mostly found in rural areas, mainly because of the limitation of medical conditions and economic sources, and they delay again and again, and when diagnosed, they are already in advanced stage, and the large treatment cost adds to the hardship of poor families, and more importantly, the treatment effect is often poor and the recurrence rate is high. Early detection, early diagnosis and early treatment of cancer not only significantly improve the survival rate, but also have a higher quality of life. Breast cancer is the number one malignant tumor among women worldwide, and it is getting younger and younger. 20 years ago, breast cancer is usually treated by radical mastectomy to remove the affected breast, followed by a combination of radiotherapy and chemotherapy. Some patients had a high survival rate, but their quality of life decreased and their self-confidence suffered, even causing family breakdown. In the past 20 years, with the advanced detection methods and the enhanced awareness of self-protection, the detection rate of early breast cancer has increased, and breast-conserving surgery has come into being. After surgery with radiotherapy and chemotherapy, there is no significant difference in efficacy compared with traditional radical breast cancer surgery, and patients are able to maintain a perfect body shape and their quality of life has increased dramatically. In order to improve the early detection and diagnosis of cancer, it is important to raise the awareness of cancer prevention among all people. Physical examination should be conducted every six months or once a year, and once suspicious lesions or any slight discomfort is found, patients should seek medical consultation as soon as possible to get a clear diagnosis and the best treatment in time. Esophageal cancer is also a common malignant tumor in China. Radiotherapy is preferred for cervical and upper thoracic esophageal cancer, and the 5-year survival rate after radical radiotherapy for early stage patients can reach 50-70%, with small side effects. In contrast, advanced patients have many complications of radiotherapy and are prone to esophageal perforation and hemorrhage and have high mortality. The incidence rate of esophageal cancer in Linzhou, Henan Province, is the highest in the world. In 1959, a research base for comprehensive prevention and treatment of esophageal cancer was established in Linzhou to explore the early diagnosis and treatment of esophageal cancer and to help establish a three-level cancer prevention network at the county, township and village levels. to 61.35/100,000.