Breast cancer is the direct results of an accumulation of mistakes in genes that occur over many years.These mistakes are called mutations. Each cell in our body has a plan. There are programmed instructions for the cells to mature, proliferative and die so that new cells can regenerate. If the cell does not follow the plan to do this, there is a mutation and that cells starts to divide uncontrollably. Copies or replicas are made and the cancer cells double in size. This process can take years. By the time a microscopic cell makes copies of itself to fill up the size of a pea, those cells were dividing anywhere from 5 to 7 years.