There are several types of breast cancer, though some are very rare. The most common form in a woman’s lobules (the part of the breast where milk develops) or in the ducts (the tiny tubes that deliver milk to the nipple). Cancer that remains in its place of origin, either in the ducts or the lobules, is considered “in situ,” or “in place.” Invasive cancer occurs when the malignant cells break through the ducts or lobules and spread to the surrounding breast tissue and/or the lymph system and other parts of the body.
Media stories and research reports often address the higher risk associated with having a BRCA mutation, but rarely discuss specific differences between BRCA1 and BRCA2. While much more research is needed, experts have already identified a few distinctions.
Ductal carcinoma in situ (DCIS) is the presence of abnormal cells in the lining of the milk ducts. Even though “carcinoma” is included in its name, DCIS is considered a precancerous condition. It is the most common type of non-invasive breast cancer, accounting for about 20 percent of new breast cancer cases.
Inflammatory breast cancer (IBC) is rare but very aggressive. It looks and acts differently than other breast cancers, and is more difficult to treat because it spreads quickly from the breast to the lymph nodes and other organs. In most cases, IBC has already metastasized by the time it is discovered.
Lobular Carcinoma in Situ (LCIS) is the presence of abnormal cells that form in the milk-producing lobules. LCIS is not cancer, but it is an indication that you have an increased risk of developing invasive cancer.