Unlike in Europe and the United States, 90% of esophageal cancers in China are squamous cancers. Studies have shown that adenocarcinoma is mostly associated with acid reflux, smoking, alcohol consumption, and obesity; whereas squamous cancer is more associated with dietary factors.
Esophageal cancer in China, “eaten out” more
Because of the specific food culture in some parts of China, most esophageal cancers are “eaten” cancers.
For example, in areas such as Anyang, Henan, where the incidence of esophageal cancer is high, residents often eat coarse, hard foods such as pancakes, and less fresh vegetables and fruits; in Chaoshan, Guangdong, where the incidence is also high, locals love to eat hot foods, such as boiling hot work tea and raw congee. These factors cause persistent damage to the esophageal mucosa, which accumulates over time and eventually evolves into cancer.
As a result, the high incidence of esophageal cancer in China shows a unique “dietary commonality”. These areas are mainly located in the Taihang Mountains of northern China (including a dozen counties and cities such as Linzhou in Henan, Magxian in Hebei, and Yangcheng in Shanxi, with a mortality rate of 100/100,000 or more), and in the Qinling and Dabie Mountains of Shaanxi, Henan, and Hubei (an irregular concentric circle formed by the eastern Qinling Mountains at the junction of Shaanxi, Henan, and Hubei provinces, with a mortality rate of 50 to 100/100,000).
Research shows that insufficient intake of animal protein, fresh vegetables and fruits, resulting in insufficient vitamins, trace elements, riboflavin, folic acid and other nutrients, leads to low immunity of the body and is one of the reasons for the high incidence of esophageal cancer.
Esophageal cancer is a “poor disease” associated with lower socioeconomic level
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The high incidence of esophageal cancer is mostly in economically underdeveloped areas, where people live in relative poverty and are less “careful” about what they eat, making them more prone to esophageal cancer. The number of cases of esophageal cancer in the rural population (17.4 per 100,000) is twice as high as the urban population (8.3 per 100,000).
Taking Lin County, Henan Province, an area with a high incidence of esophageal cancer in China, for example, the state has established a national research base for esophageal cancer prevention and treatment in Lin County since 1959. The study found that the main high-risk factors for esophageal cancer in Lin County are, poor dietary factors (moldy, pickled food, hot and hot and high salt diet), and harmful living environment (earthen latrine, drinking water pollution, etc.). Most of the above factors are related to the low economic level. For example, grain moldy still can not throw away; can not eat fresh vegetables, can only rely on pickled sauerkraut and other next meal. In Lin County, the incidence of esophageal cancer has been significantly reduced after the transformation measures such as mold prevention, de-amine, changing bad eating habits, and transforming harmful living environment.
It is worth stating that because of the new rural medical cooperative insurance and the implementation of endoscopic screening policies in some of the high incidence areas, residents in these areas have instead been able to detect esophageal cancer earlier and receive early treatment. As a result, the 5-year survival rate for esophageal cancer in China’s rural population has increased to 33.2%; however, the 5-year survival rate in the urban population is only 18%, which is still showing a downward trend.
The incidence rate is decreasing year by year
The trend of esophageal cancer incidence in some of the high incidence areas in China is similar to the national situation. from 1988 to 2003, the incidence of esophageal cancer in Linxian (now Linzhou), Henan Province, decreased by an average of 2.59% per year; from 1988 to 2007, the incidence of esophageal cancer in Magnet County, Hebei Province, decreased by 1.15% per year. In other words, the overall incidence of esophageal cancer in China has shown a trend of decreasing year by year.