What are the causes of liver cancer? How can we prevent liver cancer?

National Liver Care Day is held on March 18 every year. Since 2001, a theme has been selected every year, and liver care science and public welfare activities are carried out in various forms across the country on this day. National Liver Care Day is closely related to national public health issues that affect the country. This holiday has been widely recognized by people across the country.

1. Causes of liver cancer:

Liver cancer is the result of the synergistic effect of multiple factors, and its occurrence is multi-stage. Due to the effects of biological factors, chemical factors, etc., irreversible changes occur in the DNA of liver cells, and at the same time or followed by the cancer-promoting stage, the expression of cell genetic information is mainly changed, and immune surveillance cannot play a role, eventually forming cancer foci.

1. Viral hepatitis: Currently, the relationship between viral hepatitis and liver cancer is known to involve three types of hepatitis viruses: HBV, HCV, and HDV. In my country, HBV is the main cause of liver cancer. In countries such as Japan, HCV is the main cause. In countries such as Russia, HDV is the main cause. The World Health Organization's 1983 liver cancer prevention meeting pointed out that HBV is the second known human carcinogen after tobacco (and lung cancer). The WHO's third viral hepatitis technical advisory group meeting in 1987 pointed out that more than 40% of persistently infected people will die of cirrhosis or liver cancer caused by HBV in adulthood.

2. Aflatoxin B1 (AFB1): Epidemiological surveys in my country have repeatedly suggested that the high-incidence areas of liver cancer are the warm and humid areas along the southeastern coast where food is easily contaminated by AFB1, especially areas where corn and peanut oil contaminated by mycotoxins are consumed. In 1991, American scholar Hsu discovered at the genetic level that AFB1 is a carcinogen for human liver cancer, which attracted great attention. In a collection published in 1979, the International Cancer Research Center (IARC) has assessed that aflatoxin is a human carcinogen with sufficient evidence. HBV infection and aflatoxin intake have a significant synergistic effect on the occurrence of human liver cancer.

3. Drinking water pollution: Surveys in areas with a high incidence of liver cancer show that people who drink heavily polluted ditch and pond water have a higher liver cancer mortality rate than those who drink well water, and those who drink deep well water have the lowest liver cancer mortality rate. Recently, due to the advancement of water quality analysis technology, my country and Taiwan have found that microcystins in water have a significant effect on promoting liver cancer.

4. Trace elements: Current research on the relationship between trace elements and liver cancer has found that the mortality rate from liver cancer is negatively correlated with the selenium content in the environment and negatively correlated with the blood selenium level of residents. Animal experiments have shown that selenium can block aflatoxin-induced liver cancer in rats and ducks.

5. Heredity: In areas with a high incidence of liver cancer, liver cancer has been found to have a significant familial clustering, especially in families with blood relations, close relatives, and those living together. Chromosome analysis, cell immunity levels, DNA repair ability, and genetic markers all indicate that liver cancer has a genetic biological basis. Currently, liver cancer is considered to be a multi-gene genetic disease with a major gene effect.

To sum up, liver cancer is caused by multiple factors and multiple pathways, and the factors that cause liver cancer may be different in different regions.

2. Prevention of liver cancer:

1. Prevent hepatitis: Using hepatitis vaccines to prevent hepatitis and thus liver cancer has become one of the most promising ways to prevent liver cancer, but it is estimated that it will take decades to see results. It has been proven that hepatitis B vaccines are effective in preventing hepatitis. However, from a comprehensive perspective, prevention of HCV and HDV still needs to be considered. In addition to injecting hepatitis B vaccines, prevention of viral hepatitis also requires attention to the control of other transmission routes, such as diet, surgery, blood transfusion, injection, acupuncture and hairdressing.

2. Grain mold prevention: Mainly for corn and peanuts that are easily contaminated by AFB1. Moisture-proof storage is carried out during grain harvesting, threshing, transportation, drying, storage, etc. Grain that has been obviously moldy cannot be eaten; grain that is extremely mildly moldy is carefully selected, cleaned, and treated with drugs. In high-incidence areas, it is recommended to change the dietary structure and reduce the proportion of corn in the staple food.

3. Improve drinking water: In rural areas with high incidence, adopt a variety of measures in conjunction with the patriotic health campaign to improve the drinking water environment, switching from drinking ditch and pond water to drinking well water, deep well water, and rainwater, or building small water plants. Cities should use unpolluted water sources as tap water sources and prevent environmental pollution.

4. Appropriate selenium supplementation: For people with low selenium level, use selenium-rich yeast, selenium polysaccharides, and selenium-rich salt to supplement selenium and increase blood selenium levels.

5. Other preventive measures include reducing nitrosamine intake, quitting smoking and drinking, etc.