women s health issues
Breast Cancer
Types of Breast Cancer
Breast cancer is usually classified by the following: Type of tissue in which the cancer starts Extent of the cancer's spread Type of tumor receptors on the cancer cells There are many different types of tissue in the breast. Cancer can develop in most of these tissues, including Milk ducts (called ductal carcinoma) Milk-producing glands, or lobules (called lobular carcinoma) Fatty or connection tissue (called sarcoma): This type is rare. Ductal carcinomaaccounts for about 90% of all breast cancers. Paget Disease of the Breast None Phyllodes breast tumorsare relatively rare, accounting for fewer than 1% of breast cancers. About 10 to 25% are cancerous. They originate in breast tissue around milk ducts and milk-producing glands. The tumor spreads to other parts of the body (metastasizes) in about 10 to 20% of women who have it. It recurs in the breast in about 20 to 35% of women who have had it. The prognosis is good unless the tumor has metastasized. Breast cancer can remain within the breast or spread anywhere in the body through the Overview of the Lymphatic System or bloodstream. Cancer cells tend to move into the lymphatic vessels in the breast. Most lymphatic vessels in the breast drain into lymph nodes in the armpit (axillary lymph nodes). One function of lymph nodes is to filter out and destroy abnormal or foreign cells, such as cancer cells. If cancer cells get past these lymph nodes, the cancer can spread to other parts of the body. Breast cancer tends to spread (metastasize) to the bones, brain, lungs, liver, and skin but can spread to any area. Spread to the scalp is uncommon. Breast cancer can appear in these areas years or even decades after it is first diagnosed and treated. If the cancer has spread to one area, it probably has spread to other areas, even if it cannot be detected right away. Breast cancer can be classified as Carcinoma in situ Invasive cancer Carcinoma in situmeans cancer in place. It is the earliest stage of breast cancer. Carcinoma in situ may be large and may even affect a substantial area of the breast, but it has not invaded the surrounding tissues or spread to other parts of the body. Ductal carcinoma in situis confined to the milk ducts of the breast. It does not invade surrounding breast tissue, but it can spread along the ducts and gradually affect a substantial area of the breast. This type accounts for 85% of carcinoma in situ and at least half of breast cancers. It is detected most often by mammography. This type may become invasive. Lobular carcinoma in situdevelops within the milk-producing glands of the breast (lobules). It often occurs in several areas of both breasts. Women with lobular carcinoma in situ have a 1 to 2% chance each year of developing invasive breast cancer in the affected or the other breast. Usually, lobular carcinoma in situ cannot be seen on a mammogram and is detected only by biopsy. There are two types of lobular carcinoma in situ: classic and pleomorphic. The classic type is not invasive, but having it increases the risk of developing invasive cancer in either breast. The pleomorphic type leads to invasive cancer and, when detected, is surgically removed. Invasive cancercan be classified as follows: Localized: The cancer is confined to the breast. Regional: The cancer has invaded tissues near the breasts, such as the chest wall or lymph nodes. Distant (metastatic): The cancer has spread from the breast to other parts of the body (metastasized). Invasive ductal carcinomabegins in the milk ducts but breaks through the wall of the ducts, invading the surrounding breast tissue. It can also spread to other parts of the body. It accounts for about 75% of invasive breast cancers. Invasive lobular carcinomabegins in the milk-producing glands of the breast but invades surrounding breast tissue and spreads to other parts of the body. It is more likely than other types of breast cancer to occur in both breasts. It accounts for most of the rest of invasive breast cancers. Rare types of invasive breast cancers include Medullary carcinoma Tubular carcinoma Metaplastic carcinoma Mucinous carcinoma Rare types that typically have a poor prognosis include metaplastic and inflammatory breast cancer. Rare types that are usually associated with a favorable prognosis include medullary, mucinous, cribriform, and tubular carcinomas. Mucinous carcinoma tends to develop in older women and be slow growing. All cells, including breast cancer cells, have molecules on their surfaces called receptors. A receptor has a specific structure that allows only particular substances to fit into it and thus affect the cell’s activity. Whether breast cancer cells have certain receptors affects how quickly the cancer spreads and how it should be treated. Tumor receptors include the following: receptors grow more slowly than those that do not have these receptors, and the prognosis is better. ( Overview of the Female Reproductive System are female sex hormones.) HER2 (also called HER2/neu) receptors:Normal breast cells have HER2 receptors, which help them grow. (HER stands for human epithelial growth factor receptor, which is involved in multiplication, survival, and differentiation of cells.) In about 15% of breast cancers, cancer cells have too many HER2 receptors. Such cancers tend to be very fast growing. Sometimes cancer is also classified based on other characteristics. Inflammatory breast canceris an example. The name refers to the symptoms of the cancer rather than the affected tissue. This type is fast growing, particularly aggressive, and often fatal. Cancer cells block the lymphatic vessels in the skin of the breast, causing the breast to appear inflamed: swollen, red, and warm. Usually, inflammatory breast cancer spreads to the lymph nodes in the armpit. The lymph nodes can be felt as hard lumps. However, often no lump may be felt in the breast itself because this cancer is dispersed throughout the breast. Inflammatory breast cancer accounts for about 1% of breast cancers. 