How to get rid of cancer cells
One of the best known characteristics of cancer cells is that they divide more rapidly than most normal cells, which makes them highly sensitive to the effects of drugs that stop cells dividing. However, there are also some normal cells that divide very rapidly because they get worn out quickly and need to be replaced. Examples of normal cells that divide quickly are the cells in the bone marrow that make red blood cells and white blood cells, and the cells (epithelial cells) that line the surfaces of tissues and organs that come into contact with substances from the outside world, such as air and food.
Most chemotherapy drugs interfere with cell division and therefore kill more cancer cells than normal cells. However, chemotherapy drugs can also affect normal cells that divide rapidly, which is why many chemotherapy drugs cause side-effects such as anemia (through a lack of red blood replacement), and ulcers in the mouth and throat (through a lack of epithelial cell replacement). The effectiveness of targeted therapies is not dependent on the rate of cell division, so the types of side-effect that are commonly seen with chemotherapy are not usually associated with targeted therapies.