Normal body cells grow, divide and die in an orderly fashion. Cancer cells are different because they do not die, just continue to divide and grow. Cancer cells form as a result of damaged DNA. These damaged genes can be passed on, which accounts for inherited cancers. In other cases, the DNA is damaged by an outside source such as smoking. Cancer is the generic term used to describe a group of disorders caused by an uncontrolled multiplication of cells, which usually resulting in the destruction of neighbouring tissue