What are the specific ways of cancer metastasis?

Cancer is terrible, largely because cancer cells can spread and metastasize wildly. In the final stage, many patients feel helpless. Of course, the metastasis of cancer is divided into four stages: the better stage: invasion, in which cancer epithelial cells will loosen the connection between cancer cells. Since the bond is broken, cancer cells will naturally regain their freedom and wander freely to other places; The second stage: infiltration, the so-called infiltration, as the name implies, is internal infiltration, specifically, cancer cells enter the circulatory system through the endothelium of blood vessels or lymphatic vessels; The third stage: extravasation, which has gone through two stages: infiltration and extravasation. At this stage, the surviving cancer cells baptized by the circulatory system will pass through the endothelial cells of microvessels and reach other tissues. The fourth stage: migration, which is the last stage, is that these surviving cancer cells migrate to the new world, thrive in other tissues and form metastatic malignant tumors. Cancer cells directly invade blood vessels and will reach other parts with blood flow, such as lung, brain, liver and bone. This is blood metastasis. Gastrointestinal cancer, breast cancer, kidney cancer, etc. It often metastasizes to the lungs, and lung cancer easily metastasizes to the brain. Chemotherapy is to prevent cancer cells from transferring through blood, and to eliminate cancer cells "along the way" with drugs. Third, planting transfer: the frequency of this transfer is not high. If cancer cells fall off the tumor surface, they will "fall" in the chest cavity, abdominal cavity and cerebrospinal fluid like fruit on a tree, and take root and sprout. This is called planting transfer.