About one out of every eight women is diagnosed with breast cancer each year. Because of the prevalence of this cancer, routine mammography screenings and diligent self-examinations are very important to early detection. 75% of all breast cancers begin in the cells lining the milk ducts (ductal carcinomas). Other types of breast cancers can begin in the lobules (lobular carcinoma). If the disease has spread outside one or both of these areas, it is called invasive or infiltrating carcinoma. How the cancer is treated depends upon its origin and the degree to which it may have spread. Certain risk factors and family history can be important indicators of the likelihood of contracting breast.