Overview of Esophageal Cancer: Definition, Risk Factors, and Prevention

Esophageal cancer is a malignant tumor of the squamous epithelium of the esophagus. Its main characteristics are progressive difficulty in swallowing and retrosternal pain. Esophageal cancer tends to occur at the three physiological narrow parts of the esophagus, with the middle part being the most common, followed by the lower part, and the upper part being the least common. This disease is one of the common malignant tumors in humans. China is a country with a high incidence of esophageal cancer and also has the highest mortality rate from this disease.

The exact cause of esophageal cancer is still unclear at present, but great progress has been made based on a large amount of epidemiological data and extensive laboratory research in recent years. Especially the study of the internal and external environment in high-incidence areas has provided more and more clues and scientific evidence for suggesting the cause and conditions of the disease. The occurrence of esophageal cancer is not caused by a specific reason. The pathogenic factors are extremely complex and numerous. The occurrence of esophageal cancer is a gradual process. There must be a main factor and several secondary factors in the process of canceration, and these factors play a synergistic role in promoting cancer. Epidemiological investigations have shown that most of the high-incidence areas of esophageal cancer are economically underdeveloped areas, and esophageal cancer mostly occurs in people with poor economic conditions. Through a large number of investigations and studies in China and internationally, it is believed that it is related to chemical factors, fungal contamination, dietary habits, living conditions, smoking and drinking, and genetic factors. Psychological factors are also an important cause of this disease.



For example, in Linxian County, Henan Province, one of the high-incidence areas of esophageal cancer in China, from 1959 to 1981, during 23 years, the incidence and mortality rates of esophageal cancer remained at a relatively stable level. Although there were fluctuations, there was no obvious trend of increase or decrease. Some scholars believe that the above situation suggests that there may be a strong carcinogen in Linxian County, which is relatively constant and is less affected by human production activities. Its existence may be closely related to geographical environmental factors. The materials from Cixian County, Hebei Province, which also belongs to the Taihang Mountains, from 1974 to 1982 showed that the incidence and mortality rates of esophageal cancer in this county had a downward trend. Some scholars believe that this is related to the preventive measures taken by the county since 1974, such as improving drinking water, sunning grains to prevent mildew, advocating not eating pickled vegetables, and eating more fresh vegetables and fruits. The change in incidence further illustrates the importance of external causes. Although there is no conclusive opinion at present, some understanding has been obtained regarding various pathogenic factors.

So-called risk factors refer to anything that can increase the susceptibility to a certain disease, and different cancers have different risk factors. For example, long-term exposure to sunlight is a risk factor for skin cancer, smoking is a risk factor for lung cancer, and a high-fat, low-fiber diet increases the risk of colorectal cancer. As with most other cancers, we still don't know the real cause of esophageal cancer, but some risk factors that may increase the risk of esophageal cancer have been discovered. Modern medical research has told us that the risk factors related to esophageal cancer include genetic factors, living and dietary habits.

The high-incidence areas of esophageal cancer are distributed in Central Asia, Africa, northern France, and Central and South America. In the high-incidence areas of esophageal cancer, the content of manganese, molybdenum, iron, chlorine, zinc, sodium, selenium, phosphorus, iodine, etc. in drinking water, grains, and vegetables is relatively low. The content of nitrosamines in food is relatively high, and there is more fungal contamination. Some fungi can promote the formation of nitrosamines. Inhaling strong tobacco, chronic irritation, inflammation and trauma, such as overly hard food, overheated food, eating too fast, long-term consumption of strong alcohol, poor oral hygiene or dental caries, lack of vitamins A, B, C in food, or lack of protein, fresh vegetables and fruits in food, and genetic factors may all be related to the occurrence of esophageal cancer. In a word, there are many causes of esophageal cancer, which need to be further studied in depth.