Invasive Ductal Carcinoma - Originating in the milk ducts, this type of cancer eventually spreads to the fatty tissue of the breast. 80% of all invasive cases of breast cancer are of this type.
Ductal Carcinoma In Situ (DCIS) - "In situ" refers to the fact that the cancer is so far contained within its point of origin. In DCIS, the disease has not invaded nearby breast tissue, but is instead confined in the milk ducts. This condition has a high rate of curability, though may become invasive if left untreated.
Infiltrating (Invasive) Lobular Carcinoma - About 10 percent of all invasive breast cancer cases are of this sort, which starts in the milk-producing glands of the breast. It then spreads to surrounding areas of the breast, or even other parts of the body.
Lobular Carcinoma In Situ (LCIS) - This cancer is located solely in the lobules, or milk-producing, areas of the breast. While not technically a true cancer, the presence of LCIS should be taken very seriously as it is an indicator of the potential for more invasive types. Regular cancer screenings are recommended for women suffering from LCIS.