At present, cancer is not classified as an infectious disease in the world, and patients are not admitted and treated with the same isolation measures as infectious diseases. The incidence rate of cancer is not higher than that of the general population. Animal experiments have also shown that when cancer-stricken animals and healthy animals are kept together for a long period of time for testing, after repeated observation and examination, no contagion is seen. To the best of our knowledge, it is safe to say that cancer is not contagious. Cancer is not currently classified as an infectious disease in the world, and patients are not admitted and treated with the same isolation measures that are used for infectious diseases. The incidence of cancer is not higher among medical staff in oncology hospitals than in the general population. Animal experiments also proved that after repeated observation and examination, no contagion was seen when cancer-stricken animals and healthy animals were locked together for a long time. High-risk factors of esophageal cancer 1. Nitrosamines: Nitrosamines are strong carcinogens, among which more than 100 kinds of nitrosamines cause esophageal cancer in many animals. In the area with high incidence of esophageal cancer, different amounts of nitrosamines were found in the diet of residents, and it was also proved that the amount of nitrosamines consumed in the diet is positively correlated with the incidence of esophageal cancer. Some nitrosamines can specifically cause esophageal cancer in animals. The content of nitrosamines in the gastric juice of people in high incidence areas is significantly higher than that in low incidence areas. 2, mold: from the high incidence area sauerkraut, nest, corn flour in the separation of a variety of mold, food mold contamination rate is significantly higher than the low incidence area. Grain isolated in the wintergreen creeping stalk mold, interdigitated cross-streptospore mold has the effect of causing real change, the toxin produced can cause chromosomal aberrations. Mold and nitrosamines have a synergistic carcinogenic effect. 3, nutrition, vitamins and trace elements: the lack of certain vitamins and trace elements cause certain conditions for the development of esophageal cancer. Esophagitis, cell atypical hyperplasia and heavy hyperplasia are more common in high incidence areas, which is related to the low intake of protein, fruits and vegetables in high incidence areas. 4.Hereditary factors: There is obvious family aggregation of esophageal cancer patients. It can occur in the same family within the same generation or in several generations. Clinicians have also noticed that patients with obvious familiality are characterized by heavy symptoms, poor efficacy and short duration of disease. 5.Smoking and drinking: the increase of smoking and the prolongation of smoking time will increase the accumulation of carcinogens such as nitrosamines in tobacco in the body, and the risk of developing cancer will increase. Drinking alcohol and smoking have synergistic carcinogenic effects. 6.Hot drink and hot food: heat damage may promote the occurrence of tumor or become a condition for tumor occurrence. 7, Sauerkraut: Sauerkraut contains more nitrite and nitrite, and the carcinogenic compounds benzo(a)pyrene and other polycyclic aromatic hydrocarbon compounds have been detected in sauerkraut. It is also important to go to the hospital frequently for medical checkups and to do the screening of esophageal cancer, etc. Patients found to have severe epithelial hyperplasia of the esophagus should be given preventive treatment. Members of high-risk families aged 40-70 years old are classified as high-risk groups and are the priority targets for prevention. Education about cancer is given and participation in the initial screening screening for esophageal cancer is encouraged, and we strive for early detection and treatment.