This is the most common type of non-invasive breast cancer. DCIS means that the cancer cells are inside the ducts but have not spread through the walls of the ducts into the surrounding breast tissue. About 1 out of 5 new breast cancer cases will be DCIS. Nearly all women diagnosed at this early stage of breast cancer can be cured.
Although not a true cancer, LCIS (also called lobular neoplasia) is sometimes classified as a type of non-invasive breast cancer, and this is why it is included here. Most breast cancer specialists think that LCIS itself does not become an invasive cancer very often, but women with this condition do have a higher risk of developing an invasive breast cancer in the same breast or in the opposite breast.
This is the most common type of breast cancer. It starts in a milk passage (duct) of the breast, has broken through the wall of the duct, and invaded the fatty tissue of the breast. At this point, it may have the ability to spread (metastasize) to other parts of the body through the lymphatic system and bloodstream. About 8 out of 10 invasive breast cancers are infiltrating ductal carcinomas.
Invasive lobular carcinoma starts in the milk-producing glands (lobules). Like IDC, it can spread (metastasize) to other parts of the body. About 1 out of 10 invasive breast cancers are ILCs.
There are also some less common types, which include: inflammatory breast cancer, mixed tumors, medullary cancer, metaplastic carcinoma, mucinous carcinoma, paget disease of the nipple, tubular carcinoma, papillary carcinoma, adenoid cystic carcinoma (adenocystic carcinoma), phyllodes tumor, and angiosarcoma.
For more details on any of these topics please visit the American Cancer Society website, from which this information was taken.