Breast cancer is the second most common cancer to affect women, after skin cancer. Fortunately, early diagnosis and advances in breast cancer treatment have enhanced the chances of surviving breast cancer. It is predominantly a disease that occurs among postmenopausal women, with 70% of all cases in women older than 55 years. With the widespread use of mammography, younger women are now being diagnosed with early stage breast cancer. Approximately 227,000 women will be diagnosed with breast cancer in the United States in 2012.
Risk factors for breast cancer include family history, menstruating at an early age, taking hormones such as estrogen and progesterone, drinking alcoholic beverages and having breast tissue that is dense on a mammogram. Most breast cancer is diagnosed through a mammogram, but there are other signs such as a lump in the breast, change in size or shape, changing color or a dimple on the skin or fluid, other than breast milk, from the nipple.
Breast cancer may be broken down into two types: non-invasive and invasive tumors.
Non-invasive tumors are malignant but have not yet progressed beyond the structure from which they arise, typically the milk producing glands or ducts. These tumors are typically not palpable and are most frequently identified by routine mammography. 90% of women diagnosed with non-invasive disease are ultimately cured. The most common form of non-invasive tumor is called ductal carcinoma in situ. Invasive forms of breast cancer have spread beyond the ducts into the normal tissue of the breast. Infiltrating ductal carcinoma is by far the most common form of breast cancer, accounting for over 90% of all cases.