China is a major liver cancer country, with the third highest incidence of liver cancer among all malignancies in men and the sixth highest in women.
Why is there a high incidence of liver cancer in China?
It starts with the causes of liver cancer. in the 1960s, domestic experts began to systematically study regions with high incidence of liver cancer and discovered the culprits responsible for the high incidence of liver cancer in China: aflatoxin and hepatitis B.
The southern region with a high incidence of liver cancer in China is located in the middle and lower reaches of the Yangtze River, where food is easily moldy due to the humid climate and food storage conditions, as well as the generally high incidence of hepatitis B. These factors may be important reasons for the high incidence of liver cancer in China.
As research has progressed, experts have found that liver cancer is caused by multiple factors, through multiple pathways, and gradually develops pathological changes at different stages, eventually leading to carcinogenesis. Its etiology and pathogenesis have multiple possibilities, but the hepatitis B virus plays an important role in the development and progression of hepatocellular carcinoma.
How does hepatitis B cause liver cancer?
The hepatitis B virus is repeatedly active in the body, destroying liver cells and causing damage to liver cells, which is commonly referred to as chronic hepatitis B, or “hepatitis B” for short.
The liver is highly regenerative, and hepatocytes damaged by the hepatitis B virus continue to repair and regenerate, but this regeneration can lead to the formation of fibrous nodules in the liver, which can develop into cirrhosis over time; in addition, some of the damaged hepatocytes become malignant during the repair process, leading to the development of liver cancer.
The process of hepatitis B-cirrhosis-liver cancer is known as the three-step process of liver cancer. However, not all people with hepatitis B will develop liver cancer. The most important preventive measure for liver cancer is to prevent hepatitis B virus infection, which reduces both the incidence of chronic hepatitis B and cirrhosis, and the incidence of liver cancer.
Prevention of hepatocellular carcinoma
There are three main important preventive measures to control the development of liver cancer from its etiology.
Hepatitis B vaccination to prevent hepatitis B infection
China is both a “major liver cancer” and “major hepatitis” country. The number of people with chronic hepatitis B virus infection in China is about 93 million, because not all people with chronic infection will necessarily develop chronic hepatitis, of which about 20 million are diagnosed with “chronic hepatitis B”. Therefore, effective prevention of hepatitis B virus infection becomes particularly important.
Hepatitis B vaccination is the most effective way to prevent hepatitis B virus infection.
The main target of hepatitis B vaccination is newborns, and the current rate of hepatitis B vaccination for newborns in China is above 95%; if a mother is found to be positive for hepatitis B e antigen or surface antigen, her newborn will be given additional hepatitis B immunoglobulin within 24 hours of birth.
In these ways, the prevalence of hepatitis B infection in children has declined significantly in recent years. 2014 national epidemiological survey showed that the prevalence of hepatitis B virus surface antigen in people aged 1 to 4 years has declined by more than 60% compared to 10 years ago.
According to the mechanism of liver cancer development, hepatitis B vaccination can further prevent the development of liver cancer, which is a multi-benefit.
Anti-hepatitis B virus therapy to reduce the incidence of cirrhosis
Some people with hepatitis B can control their hepatitis activity with medications to reduce the likelihood of cirrhosis. Because complete clearance of the hepatitis B virus is extremely difficult, an important measure to prevent liver cancer in patients with hepatitis B is to suppress the activity of the virus and reduce the inflammatory response of the liver.
Patients with high levels of viral activity and recurrent abnormal liver function should be treated aggressively with anti-hepatitis B virus therapy. The commonly used antiviral drugs (e.g., lamivudine, adefovir, entecavir, etc.) have been used clinically for a long time in the treatment of hepatitis B. They are easy to take and have positive efficacy.
It is important to note that patients must follow medical advice, take their medications on time, follow up regularly, and adjust their medications in a timely manner during antiviral therapy. If you take your own medication or stop it at random, it can cause the virus to rebound and cause serious consequences.
Anti-viral therapy is also recommended for patients who already have liver cancer and who test positive for hepatitis B virus. Recent studies have shown that anti-hepatitis B virus therapy can extend the survival time of patients with liver cancer.
Regular screening for early detection of liver cancer in high-risk groups
The annual incidence of liver cancer in patients with cirrhosis is 3% to 6%, so not all patients with cirrhosis will eventually progress to liver cancer. However, because their incidence is much higher than that of the general population, cirrhotic patients are still at high risk for liver cancer and need regular hospital visits for alpha fetoprotein (AFP) and ultrasound.
In addition, people with a family history of liver cancer or chronic hepatitis B or C are at higher risk for liver cancer and also need regular alpha fetoprotein and ultrasound.
The treatment of early-stage liver cancer is significantly better than that of mid- to late-stage liver cancer, so it is important to detect the cancer as early as possible and get treatment as soon as possible to maximize the survival time of liver cancer patients.