What is the metastatic pathway of primary liver cancer

When suffering from liver cancer, cancer cells are easy to fall off due to the large intercellular space. The fallen cancer cells can be transferred to distant places through the blood, lymph and bile duct system, or directly infiltrate into adjacent organs and metastasize. Cancer cells in liver cancer tissue invade other normal tissues and cause them to become cancerous. This is cancer metastasis.

The metastatic pathways of primary liver cancer are as follows:

1. Hematogenous metastasis: Intrahepatic hematogenous metastasis occurs earliest and is the most common. It can invade the portal vein and form tumor thrombi. Tumor thrombi that fall off in the liver can cause multiple metastatic lesions. Tumor thrombi that block the main trunk of the portal vein can cause portal hypertension and refractory ascites. After invading the hepatic vein, liver cancer cells can enter the systemic circulation and metastasize outside the liver. The lung metastasis rate is the highest. It can also metastasize to various parts of the body through the blood, and organs such as the adrenal glands, bones, kidneys, and brain are more common. Hematogenous metastasis is common in hepatocellular carcinoma.

2. Lymphatic metastasis: Local metastasis to the hepatic hilar lymph nodes is the most common, and it can also metastasize to the supraclavicular, para-aortic, pancreatic, splenic and other lymph nodes. Lymphatic metastasis is the most common form of cholangiocarcinoma metastasis. Lymphatic metastasis only accounts for 12.6% of the total number of metastases.

3. Implantation metastasis: It occurs occasionally, such as implantation in the retroperitoneum to form bloody ascites, and there may also be ovarian metastatic cancer.

4. Direct infiltration: Liver cancer generally rarely directly infiltrates adjacent organs, but occasionally it can directly spread and infiltrate adjacent tissues and organs, such as the diaphragm, stomach, colon, omentum, etc.

Epidemiological surveys show that the incidence of liver cancer in China is highest in the southeastern coastal areas, with an average annual incidence of 55.63/100,000 people and a mortality rate of 47.93/100,000 people in Qidong County, Jiangsu. The mortality rate of liver cancer in Fusui, Guangxi, Shunde, Guangdong, Hunan, Sichuan and other places also ranks first among the causes of death from malignant tumors. The incidence of liver cancer in various parts of the world is higher in sub-Saharan Africa and coastal areas of Asia, while it is lower in Europe and the United States. Those with a rate greater than 5/100,000 people include Mozambique, South Africa, Nigeria, Singapore, and Uganda; those with a rate of 3.1 to 5/100,000 people include Japan and Denmark; and those with a rate less than 3/100,000 people include Europe, the United States, Australia, northern India and other regions. The disease can occur in infants from 2 months to 80 years old, with the highest age of onset being 40 to 49 years old. It is common, with a male to female ratio of 6:1.