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Basic Information

Cancer is a disease in which abnormal cells in the body grow out of control. Cancers are named after the part of the body where the abnormal cell growth begins. Breast cancers are cancer cells from the breast. When breast cancer cells spread to other parts of the body, they are called metastases.

Common Kinds of Breast Cancer

There are different kinds of breast cancer. The kind of breast cancer depends on which cells in the breast turn into cancer. Breast cancer can begin in different parts of the breast, like the ducts or the lobes.

Common kinds of breast cancer are

• Ductal carcinoma. The most common kind of breast cancer. It begins in the cells that line the milk ducts in the breast, also called the lining of the breast ducts.



• Ductal carcinoma in situ (DCIS). The abnormal cancer cells are only in the lining of the milk ducts, and have not spread to other tissues in the breast.



• Invasive ductal carcinoma. The abnormal cancer cells break through the ducts and spread into other parts of the breast tissue. Invasive cancer cells can also spread to other parts of the body.


• Lobular carcinoma. In this kind of breast cancer, the cancer cells begin in the lobes, or lobules, of the breast. Lobules are the glands that make milk.



• Lobular carcinoma in situ (LCIS). The cancer cells are found only in the breast lobules. Lobular carcinoma in situ, or LCIS, does not spread to other tissues very often.



• Invasive lobular carcinoma. Cancer cells spread from the lobules to the breast tissues that are close by. These invasive cancer cells can also spread to other parts of the body.

Uncommon Kinds of Breast Cancer

There are several other less common kinds of breast cancer, such as Paget's disease or inflammatory breast cancer. For more information about these kinds of breast cancer, visit the National Cancer Institute's General Information about Breast Cancer Treatment.