Why is the incidence of esophageal cancer in China higher than in other countries?

Esophageal cancer, also known as esophageal cancer, is a malignant tumor that occurs in the esophageal epithelial tissue, accounting for 2% of all malignant tumors. It ranks second only to gastric cancer in retrospective surveys of all malignant tumor deaths.

The incidence and mortality of esophageal cancer vary significantly around the world, and the incidence is relatively high in my country. According to surveys, nearly half of the world's esophageal cancer cases are in China. Why is the incidence of esophageal cancer in China so high?

01. Distribution map of esophageal cancer in China

I have seen many people say that "esophageal cancer was discovered because of testing", but I am skeptical about this view.

This is a distribution map of the incidence of esophageal cancer in China that I made before. Because it was in the form of a map, I changed it into a table. What is the reason for such a huge disparity in the ratio?

The calculation was done using statistics on cancer in China published in the top cancer journal CA: A Cancer Journal for Clinicians (the journal with an impact factor of 503), which is also the most authoritative statistics on cancer incidence in my country.

The original data in the figure is the number of new cases of cancer.

In order to avoid regional differences, I made a simple calculation based on the number of people in these areas, so the result is the "rate".

Of course, you don’t have to worry about whether the aging levels in different regions are different, because the data here are age-standardized.

Simply put, the age structure can be excluded to a certain extent, but the results still show very obvious differences.

The highest rate of esophageal cancer is in the southwest region, which is more than 10 times that of South China. This difference in proportion can no longer be measured simply from a detection perspective.

Also, I would like to add a piece of data: "Analysis on the Prevalence of Malignant Tumors in China in 2016", published last year. The data source is the paper by Academician He Jie from the National Cancer Center.

It can still be seen that the incidence order of esophageal cancer is actually different in different provinces (however, this is a chart of the number of cases, which is not as convincing as the previous one).

02. Causes of esophageal cancer

Regarding esophageal cancer, it is generally believed that the main carcinogenic factor is high-temperature diet. The most important factor for esophageal cancer is temperature. The World Health Organization lists high-temperature diet (over 65°C) as a carcinogen, including hot drinks such as hot coffee and hot meals.

Many people have a high demand for high-temperature diets, which can easily cause repeated injuries to the esophagus. In this case, it may provide a certain breeding ground for the occurrence of cancer.

For example, hot pot is often eaten hot right after it comes out of the pot, but this is actually risky. Not only that, peppers may also amplify the damage to a certain extent. The pain caused by peppers themselves, coupled with the TRPV1 channel, will lower the threshold for temperature perception, activate the transmission of injury signals, and trigger local inflammatory reactions.

Of course, in addition to the important reason of high-temperature diet, nitrites and other substances may also bring corresponding risks, which is related to the long-term consumption of pickled foods.

There are some common factors for other cancers, such as smoking, drinking, obesity and genetic factors.

In general, we tend to believe that lifestyle habits are an important reason.