The two most common types of breast cancer are named after the parts of the breast in which they start.
- Ductal Carcinoma: starts in the cells which line the breast's ducts, beneath the nipple and areola. The ducts supply milk to the nipple. Between 85% and 90% of all breast cancers are ductal. If the cancer is DCIS (ductal carcinoma in situ), it is well contained, not invasive, and can be very successfully treated. Usually removed during a lumpectomy, if the tumor margins are clear of cancer, follow-up treatment may include radiation. If ductal cancer has broken into nearby breast tissue (invasive cancer) then a mastectomy may be needed, and your doctor may also recommend chemotherapy.
- Lobular Carcinoma: begins in the lobes, or glands which produce milk in the breast. The lobes are located deeper inside the breast, under the ducts. About 8% of breast cancers are lobular. If the cancer is LCIS (lobular carcinoma in situ) that means the cancer is limited within the lobe and has not spread. It may be removed during a lumpectomy, if the tumor margins are clear of cancer, follow-up treatment may include radiation. If lobular cancer has spread into nearby breast tissue (invasive cancer) then a mastectomy may be needed, and your doctor may also recommend chemotherapy.
Secondmost common is a group of breast cancers that invade nearby tissue:
Invasive (Infiltrating) Breast Cancer
Invasive, or infiltrating, breast cancer has the potential to spread out of the original tumor site and invade other parts of your breast and body. There are several types and subtypes of invasive breast cancer.
This rare form of breast cancer is named for its appearance:
- Inflammatory Breast Cancer: is the least common, but most aggressive of breast cancers, taking the form of sheets or nests, instead of lumps. It can start in the soft tissues of the breast, just under the skin, or it can appear in the skin. Unlike ductal and lobular cancers, it is treated first with chemotherapy and then with surgery. When caught early, inflammatory breast cancer can be a manageable disease, and survival rates are increasing.
Least common is a cancer of the nipple, named for Sir James Paget, who first noticed the relationship between changes in the nipple and the underlying breast cancer:
- Paget's disease of the nipple/areola often looks like a skin rash, or rough skin. It resembles eczema, and can be itchy. The itching and scabs (if scratched) are signs that cancer may be under the surface of the skin, and is breaking through. Paget's is usually treated with a mastectomy, because the cancer has by then invaded the nipple, areola, and the milk ducts. Although Sir James has several other diseases named for him (bone disease and disease of the vulva) those conditions are not related to this condition of the breast.