The several types of breast cancer that can develop and related terminology are discussed. Most breast cancers start in the glandular tissue of the lobules or ducts or of the breast.
Malignant growths in the glandular tissue (ducts or lobules) of the breast are called adenocarcinomas of the breast. The two main types of breast adenocarcinomas are ductal carcinomas and lobular carcinomas.
This is a term used for early stages of a solid tumor, when the cancer cells have still not spread beyond the area where they first developed. If a breast cancer is termed in situ, it has not yet invaded any of the surrounding fatty or connective tissue, nor has it spread to any other organs of the body. In association with breast cancer, the term, in situ, refers to ductal carcinoma in situ (also called DCIS, which is cancer that is confined to the ducts of the breasts) or lobular carcinoma in situ (also called LCIS, which is cancer that is confined to the milk-producing lobules of the breasts).
Ductal carcinoma in situ (DCIS):
DCIS, also known as intraductal carcinoma, is the most common type of non-invasive breast cancer. Approximately 20% of new cases of breast cancer are DCIS. Mammography is the best way to detect DCIS early. DCIS occurs when cancer cells have filled the breast ducts but have not spread into the surrounding fatty or connective tissue of the breast or to other organs of the body. Nearly all women diagnosed with DCIS can be cured.
When DCIS is diagnosed, the pathologist runs further tests. The purpose of these tests is to see whether or not there is an area of dead or degenerating cells, which is called tumor necrosis. If tumor necrosis is detected, the DCIS condition is considered more aggressive. Comedocarcinoma is a term used to describe DCIS with necrosis.
Lobular carcinoma in situ (LCIS):
LCIS (also called lobular neoplasia) is not really cancer, but it is included in the terminology for non-invasive breast cancers. LCIS begins in the milk-producing lobules of the breast, but it does not spread beyond this area.
Although LCIS itself does not turn into an invasive form of breast cancer, women with LCIS are at a higher risk of developing breast cancer in the same breast or in the opposite breast. Because of this heightened risk, women with LCIS should have clinical breast exams 3 times a year, in addition to annual mammograms and monthly self exams.
Infiltrating (or invasive) ductal carcinoma (IDC):
The most common type of breast cancer, IDC originates in the ducts of the breast. About 80% of invasive breast cancers are infiltrating ductal carcinomas.
As its name implies, IDC is termed invasive, because the cancer has broken through the wall of the duct and invaded the fatty tissue of the breast. At this point, IDC can metastasize (spread to other parts of the body through the lymphatic system and bloodstream).
Infiltrating (or invasive) lobular carcinoma (ILC):
ILC, which originates in the milk-producing lobules of the breast, often spreads to other parts of the body.
Compared with IDCs, ILCs tend to be more difficult to detect with mammograms. ILCs represents 10% to 15% of breast cancers.
Inflammatory breast cancer:
An uncommon type of invasive breast cancer, inflammatory breast cancer accounts for only about 1% to 3% of all breast cancers. Inflammatory breast cancer involves the formation of either sheets or networks of cancer cells, rather than the development of a solid tumor. Inflammatory breast cancer is relatively aggressive in its growth.
Signs and symptoms of inflammatory breast cancer include the following possible changes in the skin of the affected breast:
ē A red, pitted, and thick appearance
ē Feeling warm to the touch.
The changes in appearance and warmth are not the result of infection, but are caused by breast cancer cells blocking lymph vessels or channels in the skin.
Representing about 5% of breast cancers, medullary carcinoma is an uncommon type of invasive breast cancer. Medullary carcinoma has several special features, including a rather well-defined, distinct boundary between tumor tissue and normal tissue; the large size of the cancer cells; and the presence of immune system cells at the edges of the tumor.
The likely outcome (prognosis) for medullary carcinoma is better than for other types of invasive breast cancer.
Also called colloid carcinoma, mucinous carcinoma is a rare form of invasive breast cancer that stems from mucus-producing cancer cells. The survival rates for mucinous carcinoma are higher than for more common forms of invasive breast cancer.
Pagetís disease of the nipple:
A rare form of breast cancer, Pagetís disease of the nipple represents less than 1% of all breast cancers. Pagetís disease develops in the breast ducts, then spreads to the nipple skin, and the areola (the dark circle around the nipple). Often, Pagetís disease is associated with in situ carcinoma or infiltrating breast carcinoma.
The nipple and areola of a woman suffering with Pagetís disease often appear scaly, red, and crusted. Also in Pagetís disease, bleeding, oozing, itching, and a burning sensation in the breast area are common.
Despite these unsettling symptoms, the prognosis for women with Pagetís disease is better, if a lump has not been detected in the breast tissue and a biopsy has determined that there is no invasive cancer.
Phyllodes (also called Phylloides) tumor:
An extremely rare type of breast tumor, Phyllodes tumors develop in the stromal (connective) tissue of the breast.
Although Phyllodes tumors usually are benign (i.e., non-cancerous), they occasionally can be malignant (i.e., cancerous). In the past, both benign and malignant phyllodes tumors were termed cystosarcoma phyllodes.
Phyllodes tumors cannot be treated with hormone therapy, and they seldom respond to either chemotherapy or radiation therapy. Benign phyllodes tumors are treated by surgical removal of the mass and a small portion of the surrounding normal breast tissue. Malignant phyllodes tumors are treated by surgery, involving either removal of the tumor and a wider margin of the normal breast tissue, or mastectomy.
An uncommon type of infiltrating breast carcinoma, tubular carcinomas represent approximately 2% of all breast cancers. Tubular carcinomas have a better prognosis than do more common types of invasive breast cancer.