Breast cancer is the most common cancer among women of all ages.
It is the leading cause of death, from all causes, of women between the ages of 35 and 54. Until we know more about preventing breast cancer, detection of breast cancer at an early stage provides a greater chance of survival and more treatment options. Once breast cancer has been found, more tests will be done to find out if the cancer has spread from the breast to other parts of the body. This is called staging. To plan treatment, a doctor needs to know the stage of the disease.