FACTS: Breast cancer usually begins as a lump that can be seen in a mammogram or felt when the breast is examined. Fortunately, the majority of breast lumps are non-malignant cysts or fibrous tissue. But sometimes lumps are formed when good cells turn bad and start multiplying rapidly to form a tumor.
The exact causes of these malignant mutations are unknown, so it is impossible to predict accurately who will develop them. However, risk-factors that increase the probability of developing the disease include a family history of breast or ovarian cancer, increasing age, never having breastfed, never having given birth, long-term hormone replacement therapy, and smoking. (Men can get breast cancer, too. There is a small amount of breast tissue, consisting mainly of ducts, in the male chest, and about 1% of breast cancers occur in men.)
Depending on the type and stage of the tumor, treatment may include surgery, chemotherapy, hormone therapy, biologic therapy, and radiotherapy. (Chemotherapy works by killing cells that are actively dividing, which is why even healthy cells that grow constantly, such as those that produce hair, are impacted.)
Although breast cancer is extremely serious, most people (approximately 80%) who get it survive, particularly if treatment is initiated early in the course of the disease before it has spread from its original site. Self-examination and regular checkups are critical for early detection.