However, if you inject some radioactively labelled cells into the blood, most of them die. Cell sticks to the wall of a blood vessel 2. Cancer cells can sometimes stimulate the formation of a blood clot and this is an alternate way to stick and stop. If you get a clot in your brain you could die. E. Cell leaves blood vessel.
Blood vessels have a lining of a layer of cells.
For a cancer cell to leave the blood vessel, it has to narrow down to a point at one end and then squeeze itself between two of the cells in the lining of the vessel. These lining cells are called endothelial cells. The cancer cell got into the blood vessel in the same way, by squeezing between two cells. After the cell leaves a blood vessel somewhere in the body, it invades surrounding tissue and then divides to make a new tumor or second colony. For a primary tumor at one site, secondary tumors are more likely at certain specific sites.