Breast cancer occurs when there is a malignant tumor inside the breast. Each year more than 185,000 women are diagnosed with breast cancer, and the incidence of this disease is rising in developed countries. There are approximately 43,500 deaths from breast cancer annually, making this disease second to lung cancer as the leading cause of death by cancer among women. Ninety percent of breast cancers are detected by women themselves, often through breast self-examination (BSE). Larry Norton, MD, President of the American Society of Clinical Oncology described the basics of cancer on a cellular level in an interview with the Discovery Health Network, "All the tissues in the body know to grow to a certain size and to perform certain functions. When something goes wrong with the instructions in certain cells, they do several things that are abnormal, and these are things that we call cancer. Too many cell divisions occur so you can get a lump, a mass. These cells spread into surrounding tissue and develop the capacity and this is the serious part-to grow in other parts of the body." From this very general explanation of how cancer works, we can begin to understand what is really occurring during the development of breast cancer.
             There are three general stages of the development of breast cancer: the abnormal accumulation of breast cells leading to the formation of a lump, the dispersion of the abnormal cells into surrounding tissue, and further spreading of the cells to other parts of the body. When a breast cell is normal a small collection of cells exist in various locations within the breast. However, if the breast cells begin to mutate and multiply uncontrollably into a large mass, a lump develops. It can then invade into the surrounding breast tissue and then become invasive breast cancer. If it spreads to other parts of the body such as the lymph nodes under the arm, the lung, liver, or bone you call that metastasis. The cancero...