Where are people prone to colorectal cancer?

First, geographical distribution The difference in the incidence of colorectal cancer around the world can reach more than 20 times. Developed countries such as Northern Europe, Western Europe, North America and New Zealand (except Japan and Finland) have the highest incidence of colorectal cancer. Some countries with more developed social economy, such as southern Europe, eastern Europe and Latin America, have a middle incidence rate, while Asia, Africa and most underdeveloped Latin American countries have the lowest incidence rate. The difference of economic development may be an important factor in the incidence of colorectal cancer among residents. It is generally believed that the incidence of colorectal cancer in western developed countries is significantly higher than that in developing countries. According to the data of IARC 1982, among 105 countries and regions in the world, the highest annual incidence rate of colorectal cancer is in Connecticut (23.3/65438+ 10,000), followed by new york (3 1.4/65438+ 10,000), and the lowest is in Dakar (0. According to WHO statistics, the highest mortality rate of colorectal cancer in the world is New Zealand, with an adjusted mortality rate of 23.96/65,438+10,000. Some European countries also have higher mortality rates, such as Denmark 2 1.39/65438+ 10,000, Austria 19.28/65438+ 10,000, and England and Wales 65438+. The United States has the highest mortality rate (16.58/65438+ 10,000), and Asia has the highest mortality rate (16.44/65438+ 10,000). China is at a low level in the world. The incidence of colorectal cancer in China is one of the low-level countries, and its distribution trend is similar to that in the world, that is, the incidence of colorectal cancer in economically developed areas is higher than that in economically underdeveloped areas. Second, the population distribution is 1. The incidence of colorectal cancer in men and women is close worldwide, and the surname of men is slightly higher than that of women. With the increase of age, the incidence of colorectal cancer gradually increased, and the incidence of colorectal cancer decreased slightly in the age group over 85. In recent years, young people's colorectal cancer has attracted much attention. Studies have shown that colorectal cancer in young people may be closely related to genetic factors. The median age of patients with colorectal cancer in China is 45 years old, which is earlier than 55 years reported in Europe and America 10 years old. It can be seen that although the incidence of colorectal cancer in China is lower than that in Europe and America, the target of harm is younger than that in Europe and America. 2. Race and heredity According to the data, the high incidence of colorectal cancer in the world is white, followed by black, and the incidence rate of Asians and American Indians is the lowest. Therefore, it is suggested that the incidence of colorectal cancer is related to human race. However, according to IARC data, the annual incidence of colorectal cancer in China is 25/65438+ 10,000, and that in Japan is 30.8/65438+ 10,000, both of which are significantly higher than those in the United States. The incidence of colorectal cancer among blacks living in Mozambique is the lowest in the world, but the incidence of colorectal cancer among black descendants who immigrated to the United States is close to that of white Americans and far exceeds that of native Japanese. The incidence of colon cancer in Poland is lower than that in the United States. The incidence of colon cancer among Polish immigrants to the United States is similar to that of Americans, and the incidence of colon cancer among Polish immigrants to Australia is higher than that of Polish natives. The above-mentioned immigration epidemiological data strongly suggest that colorectal cancer is a typical environmental lifestyle cancer, and ethnic inheritance plays a negligible role in its etiology, while lifestyle, diet structure and environmental factors may be the main causes. 3. Studies of other social groups show that the incidence of colorectal cancer is positively correlated with economic income and education level. The incidence of colorectal cancer in religious people who eat meat is higher than that in vegetarians. According to the statistics of California and Colombia, the risk of colorectal cancer is four times that of low social class in all ages. Domestic data show that the incidence of colorectal cancer in urban areas is higher than that in rural areas, and the larger the city, the higher the mortality rate. Third, the incidence trend In the past 20-30 years, the incidence of colorectal cancer has risen faster than that of lung cancer in many areas, ranking first in the increase. In the United States 1974, there were 99,000 new cases of rectal cancer in China, and 1984 increased to130,000 cases, and 1990 reached155,000 cases.