(1) Dietary habits and esophageal cancer Investigating the incidence factors of esophageal cancer in high incidence areas, it was found that patients with esophageal cancer have the habits of coarse food, eating too fast and preferring hotter food, which can damage the epithelium of esophagus and increase the sensitivity of esophagus to carcinogens. The temperature of food in the bowl of residents in the high incidence area when eating was measured and could be as high as 70-80℃, with the highest being 80-88℃. Higher food temperature is one of the causative factors for the development of esophageal cancer. Experimental studies on mice fed with hot water at 75℃ caused epithelial cell degeneration, mucosal inflammation and cellular nucleic acid metabolism were affected, and long-term repeated thermal stimulation contributed to esophageal carcinogenesis. Fast eating, coarse food, squat eating, strong tea drinking and irregular meals are related to esophageal cancer. (2) Smoking and esophageal cancer A lot of epidemiological surveys have been conducted on esophageal cancer in high and low incidence areas as well as urban and rural areas, and smoking may also be a cancer-promoting factor that cannot be ignored in the occurrence of esophageal cancer in China. Tobacco is a carcinogenic substance and its harm to human body is multi-effective. The carcinogenic substances in tobacco can be swallowed with saliva or food to the esophagus or absorbed and act on the esophagus to cause carcinogenesis. Cigarette smoke and tar contain a variety of carcinogens, such as benzo alpha pyrene and other polycyclic aromatic hydrocarbons, epoxides, lactones, peroxides and haloethers, and contain a variety of nitroso compounds such as nitrosopyrrolidine, dimethylnitrosamine, nitrosodeoxynicotine or nitroso-neonicotine. Smoke also has a large number of NO, NO2 and hydrocarbon reactions generated alkanes and alkoxy radicals, these components can directly damage cellular fats, proteins and nucleic acids and other components, resulting in cell damage and causing cancer. Several chemicals in tobacco were added to drinking water and fed to rats for 30 weeks. As a result, more than 50% of the rats given nitroso-normethylnicotine developed esophageal tumors, including three cases of esophageal cancer, further confirming the relationship between tobacco and esophageal carcinogenesis. (3) Alcohol consumption and esophageal cancer Alcohol itself may not be directly carcinogenic, but it has a pro-carcinogenic effect. Alcohol can be used as a solvent for carcinogens and promote carcinogens to enter the esophagus, causing damage to the esophageal mucosa and creating conditions for the occurrence of esophageal cancer. Studies have found that some alcohol may be contaminated with nitrosamines, polycyclic aromatic hydrocarbons, phenolic compounds, DDT, etc. These contaminants may enhance the damage of alcohol to the esophageal mucosa. Numerous epidemiological surveys have found that many patients with esophageal cancer have a history of heavy alcohol consumption or are mostly brewery workers and employees associated with wine merchants. Recently, British and Hong Kong scientists investigated the smoking and alcohol consumption of esophageal cancer patients in Hong Kong and found that alcohol consumption may be more likely to cause esophageal cancer than smoking after detailed comparative analysis. In China, a survey was conducted on 1400 esophageal cancer patients, and 26.9% of the incidence group had a history of alcohol consumption (more than 2 taels of liquor per week on average for more than 5 years). (4) Chronic irritation of esophagus Some pathogenic factors can cause irritation of esophagus, and long-term repeated irritation will further lead to esophageal mucosal lesions. Some esophageal lesions, such as esophageal cardia failure, chronic esophagitis, benign esophageal stricture and esophageal mucosal leukoplakia, have a higher incidence of esophageal cancer, indicating that the stimulation caused by chronic inflammatory damage plays a role in the development of esophageal cancer.