Original Singularity Cake According to the 2020 Global Cancer Statistics Report, the number of new cancer cases in China is 4.57 million, accounting for 23.7% of the world; the number of deaths is 3 million, accounting for 30% of the world [1, 2]. It can be seen that China has be

Original Singularity Cake

According to the 2020 Global Cancer Statistics Report, the number of new cancer cases in China is 4.57 million, accounting for 23.7% of the world; the number of deaths is 3 million, accounting for 30% of the world [1, 2]. It can be seen that China has become a major cancer country. Over the past four decades, the Chinese government has conducted three registration surveys on cancer, aiming to better assess the burden on cancer.

The first survey recorded data from 395 cities and 2392 counties between 1973 and 1975, covering 96.7% of the country's population [3, 4]. Afterwards, the Chinese government began to formulate corresponding guidelines and establish health care facilities. The second and third registration surveys were between 1990-1992 and 2004-2005, respectively, with the aim of assessing long-term changes in cancer burden [5, 6].

Subsequently, the Chinese government gradually established a cancer registration website, regularly collecting data on cancer incidence and mortality, and establishing a national cancer registration center. The number of centers has been increasing, from 43 in 2008 to 574 in 2019, and the cancer statistics network has gradually matured [7].

Recently, Professor Ye Weimin's team analyzed the cancer statistics in China in the past 40 years. The results showed that since 1975, the mortality rates of gastric cancer , esophageal cancer and liver cancer have been at a relatively high level, and have begun to show a downward trend in the past decade. The incidence of common cancers in developed countries such as lung cancer, female breast cancer and colorectal cancer is rapidly increasing .

At the same time, with the process of urbanization, there are already great differences in the high incidence of cancer in rural areas and urban areas in my country. Researchers pointed out that establishing and improving primary public health systems is the key to effective intervention in cancer . Related research results are published in the journal Cancer Newsletter [8].

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researchers used three cancer survey data and the latest National Cancer Registration Center data (2016) to analyze and compare the changes in cancer mortality rate and major cancer rankings in space and time. Mortality is an age-standardized mortality based on the world's standard population (Segi population data). The analysis of the geographical distribution characteristics of cancer is based on the hot spot marking map of cancer on China map. Data from urban areas in China show that from 1973 to 2016, the mortality rates of lung and colorectal cancer gradually increased, while the mortality rates of esophageal and gastric cancer decreased significantly. 2016, lung cancer, liver cancer, gastric cancer, colorectal cancer and female breast cancer ranked among the top five cancer mortality rates in urban areas. Data from rural areas in China show that the mortality rates of the five major cancers in rural areas between 1973 and 1975 were roughly the same as those in small-scale urban areas; in addition, the mortality rate of lung cancer in rural areas at this stage was the lowest, and then grew rapidly, reaching nearly the same level as in urban areas in 2016. In 2016, compared with the first three time periods, the mortality rates of esophageal cancer and gastric cancer in rural areas decreased, with lung cancer, liver cancer, gastric cancer, esophageal cancer and colorectal cancer in the top five mortality rates, which is different from those in urban areas.

Age standardized mortality rate for major cancers in different regions and different time periods

1973-1975 China stipulated a batch of high-risk geographical areas for cancer species, including gastric cancer, esophageal cancer, liver cancer, lung cancer, colorectal cancer, and breast cancer. This study analyzed the changing trend of age standardized mortality rates of gastric cancer, esophageal cancer and liver cancer in these high-risk areas over time. High-risk areas for gastric cancer include Liaodong Peninsula , Shandong Peninsula , Yangtze River Delta , Taihang Mountain , Hexi Corridor and eastern coastal areas. The high mortality rate of gastric cancer may be related to the dietary habits of these areas that prefer high salt and pickled vegetables [9, 10]. From 1990 to 2004, the age standardized mortality rates of gastric cancer in Changle City, Fujian, Wuwei City, Gansu, and , Zhangye City, and Shexian County, Hebei Province decreased significantly.However, 2016 survey data showed that the age-standardized mortality rate of gastric cancer in these high-risk areas is still more than twice the national level.

1973-1975 The age standardized mortality rate in gastric cancer in the other three time periods

Henan, Shanxi and Hebei are high-risk areas for esophageal cancer [4], which is also closely related to the dietary habits in these areas, such as hot food and alcohol consumption [11]. The standardized age mortality rate of esophageal cancer in all high-risk areas showed a gradual decline from 1990 to 2016. The survey results from 2004-2005 and 2016 show that the mortality rate of esophageal cancer in high-risk areas has decreased significantly compared with 1990-1992, especially Ci County, Hebei Province, Yangcheng, Shanxi Province and Pingshun County, . However, from to 2016, except for Yangcheng and Pingshun County, Shanxi, the mortality rate of esophageal cancer in other high-risk areas was still more than twice the national level.

1973-1975 In the high-mortality areas that have been identified in the other three time periods, the southeast coastal areas are high-risk areas for liver cancer death. One of the reasons may be that the staple foods in these areas, including corn, peanuts, etc. are more susceptible to the contamination of aflatoxin [12]. Survey data from 1973 to 1975 showed that Shanghai had the highest mortality rate of liver cancer, followed by Fujian, Guangxi, Jiangsu, Zhejiang and Jilin Provinces [4]. Compared with 1990, the age-standardized mortality rates of liver cancer in Jiangsu Haimen and Qidong , Fujian Xiamen and Changle , and Zhejiang Jiashan all showed a significant decline in age, and were close to the national level in 2016. However, the liver cancer mortality rate in Fusui Region of Guangxi Zhuang Autonomous Region showed an upward trend. In 2016, the liver cancer mortality rate in men in the region was 4.6 times that of the national level and 3.7 times that of women.

1973-1975 Hepatitis cancer age standardized mortality rate in the other three time periods

Overall, three national surveys and the latest cancer registration data show that China's cancer mortality pattern is in the transition stage between developing and developed countries. The mortality rates of major cancers, including gastric, esophageal and liver cancer, have been at a relatively high level since 1975 and have begun to decline in the past decade. Meanwhile, other cancers that usually have higher mortality rates in developed countries, such as lung cancer, female breast cancer and colorectal cancer, have grown rapidly in China in a short period of time. In terms of regional distribution of cancer, 10 years ago, the top five cancer types in rural areas in China were similar to those in urban areas. In 2016, there was a difference in the main types of cancer in rural and urban areas in China. At the same time, the top five cancer types in urban areas were the same as the global regional statistical results in 2020 [13]. It can be seen that the cancer mortality pattern in in China is also changing with urbanization. researchers pointed out that establishing and improving primary public health systems is the key to reducing the burden on cancer in China. Due to China's vast territory, unbalanced development and cultural diversity, it is necessary for us to take flexible and diverse measures to intervene in cancer. In addition, the lack of screening facilities and medical service staff in some areas, especially in rural areas, is a problem that cannot be ignored. While facing many challenges, science and technology have also brought us new opportunities, such as artificial intelligence and the emerging new biomarker . In addition, the gradual improvement of China's cancer registration investigation system will help promote the deployment of cancer prevention strategies.