Cancer is thought to develop as a consequence of genetic damage in normal cells. The damage can be congenital (10-15 percent of cancer cases) or be caused by, for example, external factors. The cell contains genes which in turn contain germ plasma (DNA) that determines how the cell’s proteins are to be produced. Cancer develops when a string of mutations take place in genes that govern the cell’s ability to grow and divide. These mutations often lead to an overstimulation of cell growth a