According to the American Cancer Society, over 250,000 new breast cancer cases were diagnosed in 2009 in the U.S., in both women and men, with women having the highest prevalence. Breast cancer starts in the breast tissue, and is categorized by cancer cells appearing in or surrounding the tissue. A woman's (and man's) breast tissue is comprised of ducts, lobes, muscle, fatty and lymphatic tissue, and glands for milk production.
Approximately 15 types of breast cancer exist today, along with many stages from stage one to four. Where and how the breast cancer shows up determines the diagnosis and subsequently, treatment. The four most common include ductal and lobular in situ, invasive or infiltrating carcinoma, inflammatory, and Paget's.
In Situ: Ductal and Lobular Carcinoma
There are two types of in situ cancers: ductal and lobular. Ductal carcinoma begins in the duct wall and invades connective and fatty breast tissue. Lobular carcinoma in situ develop in the lobes of the breast. The most common of all non-invasive breast cancer diagnoses is ductal carcinoma in situ. Breast cancer still contained within the breast wall is "in situ"--meaning "in the original position." The cancer cells and developing tumor stay inside the breast tissue itself and the surrounding tissue remains unaffected. The tumor does not move or infiltrate other parts of the breast and can appear encapsulated within the breast, like a bubble.
Invasive Carcinoma
Invasive or infiltrating carcinomas affect both ducts and lobes and are the more aggressive type of cancer. As the name states, the cancer cells invade other areas of the breast. With in situ, the cancer cells stay put. However, invasive cancer cells move from their origin in the lobe or duct and break through the tissue walls into other areas of the breast like the fatty and/or connective tissue. Once cancer cells move, their access to other parts of the body increases through blood vessels.
Inflammatory Breast Cancer
Only 1 percent of all breast cancer diagnoses will be inflammatory. Inflammatory breast cancer grows rapidly and is localized within the breast tissue. It is much like invasive carcinomas, spreading within the breast. As one of the most aggressive cancers, it moves into the lymphatic system and is not contained with the removal of the breast (mastectomy). It is treated as aggressively as possible.
Paget's Disease
Paget's disease, a breast cancer, is associated with nipple changes in addition to the presence of cancer cells within the breast tissue. The difference between Paget's and other breast cancers is in Paget's the cancer cells break off from a tumor in the breast tissue and move into the milk ducts, instead of starting in the ducts and moving outward into the breast tissue.
References
- Interview with Michele M., breast cancer survivor, February 15, 2010
- American Cancer Society
- Mayo Clinic: Breast Cancer
