How does chemotherapy fight cancer?
(Lansing State Journal, July 26, 1995)
In the case of cancer, the growth regulating genes in the cell have mutated, often because of some outside carcinogen such as cigarette smoke, and no longer function to control the growth of the cell.
This causes the cell to grow and divide very rapidly, compared to a normal cell, and a tumor is formed which eventually invades surrounding tissues. Since these cancer cells are growing and dividing much more rapidly than normal cells, they take in many more nutrients than the normal cells in the body.
This is where chemotherapy comes in. Basically the idea behind chemotherapy is to give the patient poison in doses that are toxic but low enough not to kill the patient.
Since cancer cells are growing so rapidly and taking more nutrients in from the surroundings than normal cells, they are also taking in higher doses of poison than the other cells. If we're lucky, the chemotherapy will kill the cancer cells and cure the patient.