The larynx is lined with cells which grow rapidly before birth and during child- hood through puberty. In the adult, however, new cell production is under very tight control. New cells are produced by division of older ones to replace those lost due to old age and injury. Normally, if the genes are damaged, the cell won't divide at all. However, due to particular types of gene damage, the cell may start dividing out of control.
Cancer starts in a single cell, when it starts dividing out of control.
When cells divide rapidly, they form a clump of cells known as a tumor. A tumor merely means a swelling, it can be caused by most any infection or irritation and is not necessarily cancer. The most common organs for cancer to spread to in the bloodstream are the lungs, liver, bone and brain. It is important to catch and treat cancer early, for the longer and larger it grows, the more the chance of distant spread. Each year in the United States there are 12,500 new cases of larynx cancer which leads to about 800 deaths.