Terms Associated with Metaplastic Breast Cancer

Here is a list of important breast cancer and metaplastic terms and abbreviations you may see when researching MpBC.

Abnormal cells: Cells that do not look or act like the healthy cells of the body.

Atypical ductal hyperplasia: Abnormal cells that have accumulated in a breast duct. The cells have increased in number and fill almost the entire duct. The cells can keep changing until they become DCIS. Atypical ductal hyperplasia can increase the risk of a future breast cancer.

Atypical lobular hyperplasia: Abnormal cells that have accumulated in a breast lobule. The cells have increased in number and fill almost the entire lobule. It’s possible for the cells to keep changing until they become LCIS. Atypical lobular hyperplasia can increase the risk of a future breast cancer.

Advanced Cancer: Cancer that has spread outside of the breast and into other plarts of the body and usually cannot be cured or controlled with treatment. See Metastatic

Angiogenesis Angiogenesis, the growth of new capillary blood vessels in the body, is an important natural process in the body used for healing and reproduction.

Aromatase Inhibitor: (uh-ROH-muh-tayz in-HIH-bih-ter): A drug that prevents the formation of estradiol, a female hormone, by interfering with an aromatase enzyme. Aromatase inhibitors are used as a type of hormone therapy for postmenopausal women who have hormone-dependent breast cancer.

Axilla: The underarm or armpit.

Axillary lymph nodes: The lymph nodes under your arms.

Basal-like breast cancer: Basal-like is one of the four main molecular subtypes of breast cancer. Basal-like breast cancer is hormone-receptor- negative and HER2-negative. Also called triple-negative breast cancer. However, MpBC is NOT basal-Like breast cancer. It only shares the triple negative features. MpBC are the claudin-low subtype.

Benign: (beh-NINE): Not cancer. Benign tumors may grow larger but do not spread to other parts of the body.


Biopsy: (BY-op-see): The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue.

Breast Cancer: Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It is one of the mostcommon malignancies in women in the US.

Breast-conserving surgery: Surgery designed to conserve as much of the breast as possible. A lumpectomy is a breast conserving surgery.

BRCA1 Mutations: An abnormal gene, known as BReast CAncer gene 1, associated with a higher risk of developing breast cancer.

BRCA2 Mutations: An abnormal gene, known as BReast CAncer gene 2, associated with a higher risk of developing breast cancer.

Bilateral mastectomy: When both breasts are surgically removed during one operation. It is very rare for a woman to have cancer in both breast simultaneously so the removal of both breasts is not medically necessary in most cases. However, some women at high risk chose to have one (or both) breast removed prophetically to insure they don not get cancer or their cancer doesn’t return.

Cancer: Normal cells are very orderly in their replication process. As one cell dies an single exact duplicate cell is created to take its place. With cancer this process is interrupted in two ways. First, the cell creates more than one duplicate and replicates in an uncontrolled manner. This is called hyperplasia. Second, the new cells are not normal. They take on an abnormal appearance that eventually becomes so abnormal (Atypia) that it looks nothing like the original cell. When these two problems occur at the same time you have cancer. Unchecked, cancer cells can also spread to other parts of the body through the blood and lymph systems.

Carcinoma: Simply put carcinoma is cancer.

CAT or CT Scan:(Computerized Tomography): A computerized scan that allows your doctor to see internal organs for diagnostic purposes.

Cell: The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.


Chemotherapy: Treatment with drugs that kill cancer cells.

Clinical trial: A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

Contrast Material: A dye or other substance that helps show abnormal areas inside the body. It is given by injection into a vein, by enema, or by mouth. Contrast material may be used with x-rays, CT scans, MRI, or other imaging tests.

Cysts: A fluid-filled sac.

(DCIS) Ductal Carcinoma In Situ: A noninvasive condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, ductal carcinoma in situ may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive.

Disease free survival: This is not the same as survival or overall survival rate. This is the rate at which you can expect to live without a recurrence. Example: If MpBC has a five year DFS rate of 50% that means 50% of women diagnosed with MpBC will live five years without a recurrence or progression of the disease. Often this number is lower than the OS rate but does not reflect on the OS rate or your chance of surviving this cancer.

Estrogen: A type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones.

External radiation therapy A type of radiation therapy that uses a machine to aim high-energy rays at the cancer from outside of the body. Also called external-beam radiation therapy.

Epithelial to Messechymal Transition (EMT):EMT is the process by which epithelial cells change into messenchymal cells. This transition is the hallmark of metaplastic breast cancer.


Gland: An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk.

Grade: Grade is how different the cancer cells are from normal cells. Experts compare the appearance of the cancer cells to normal breast cells. Based on these comparisons, they give a grade of between 1 and 3 to the tumor. A lower grade tumor is considered less aggressive and a grade of 3 more aggressive. The grade is different from stage.

Hormone receptor status: Your hormone receptor status indicates if your tumor over expresses estrogen or progesterone. These two hormones help fuel the growth of about 80% of breast cancer tumors. Your hormone receptor status will also indicate if your tumor is affected by the protein HER2. If your tumor is not affected by these it is referred to as “triple negative.” Most metaplastic breast cancers are triple negative or very weakly affected by ER, PR or HER2.

HER1: Also referred to as EGFR (Epidermal Growth Factor Receptor) A protein involved in normal cell growth. The overexpression of EGFR has been associated with some kinds of metaplastic breast cancer, making HER1 a potential target for new drugs. Two drugs are already available targeting this protein.

HER2: A protein involved in normal cell growth. It is found on some types of cancer cells, including breast and ovarian. Cancer cells removed from the body may be tested for the presence of HER2/neu to help decide the best type of treatment.

Heterogeneous Disease: Means that it has many subtypes but is defined primarily by the way the cancer cells involved change in form

Hormone therapy: Hormone therapy is given as a part of breast cancer treatment after surgery, chemo and/or radiation. Hormone therapy is recommended if your tumor is hormone receptor positive. (see above) Tamoxifen is one example of a hormone therapy. It is given in pill form for five years after other treatment has been completed. Hormone therapy helps lower the chances of recurrence. MpBC is often hormone receptor negative (not always) which makes hormone therapy ineffective an therefor unnecessary.

Inflammatory breast cancer: A rare and aggressive type of breast cancer in which the breast looks red and swollen and feels warm. The skin of the breast may also show the pitted appearance called peau d’orange (like the skin of an orange). The prognosis for IBC is worse than for more common invasive ductal/lobular carcinoma.

In situ: Also called stage 0 disease. Condition where abnormal cells are found in the milk ducts or lobules of the breast, but not in the surrounding breast tissue. In situ means “in place.” See ductal carcinoma in situ and lobular carcinoma in situ.

Invasive Ductal Carcinoma (IDC): The most common type of breast cancer. It begins in the cells that line the milk ducts in the breast.

Invasive lobular carcinoma: Cancer that begins in the lobules of the breast. It is less common than invasive ductal carcinoma.

Lumpectomy: Surgery to remove abnormal tissue or cancer from the breast and a small amount of normal tissue around it. Sometimes referred to as “breast conserving surgery.”

Lymph node: A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. The lymphatic system acts as a filter for the body and help the body fight infection. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells).

Lymphedema: A condition in which excess fluid collects in tissue causing swelling. It may occur in the arm or leg after lymph node dissection or removal in the underarm or groin. In the past when Axillary Node Dissection was a standard procedure during breast cancer surgery, lymphedema was more common. These days a surgeon will attempt to perform a sentinel node dissection first. If no cancer is found in the sentinel node the full ALND will not be performed. Lymphedema is much less common with the SND.


Malignant: Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.

Mammogram: An x-ray of the breast.

Mastectomy: Surgery to remove the breast (or as much of the breast tissue as possible). Other types ofmastectomy.

Matrix Producing:A sub-type of MpBC “with a direct transition of carcinoma to cartilaginous or osseous matrix without an intervening spindle cell component.”

Medical oncologist: A doctor who specializes in treating cancer using chemotherapy, targeted therapy, hormonal therapy, and biological therapy. A medical oncologist often is the main health care provider for someone who has cancer. A medical oncologist also gives supportive care and may coordinate treatment given by other specialists.

Menopause: The time of life when a woman’s ovaries stop working and menstrual periods stop. Natural menopause usually occurs around age 50. A woman is said to be in menopause when she hasn’t had a period for 12 months in a row. Symptoms of menopause include hot flashes, mood swings, night sweats, vaginal dryness, trouble concentrating, and infertility.

Metastatic Breast Cancer (MBC): This should not be confused with metaplastic Breast Cancer. Metastatic Breast Cancer means that the cancer has moved outside of the breast tissue and into other distant areas of the body. Often this can be the lungs, bones, brain or liver. Metastatic Breast Cancer is considered incurable.

METS: METS refers to metastatic breast cancer. See above.

MpBC: Metaplastic breast cancer. On this site we refer to metaplastic breast cancer as MpBC so as not to be confused with MBC (Metastatic Breast Cancer). However, you will see MBC used in some studies to refer to metaplastic breast cancer. In order to make a distinction on this site we use MpBC.

Metaplastic: Metaplastic means “to change form.” The hallmark of metaplastic breast cancer is the change in cells from epithelial to mesenchymal, called EMT.

Metaplastic Carcinoma: This is the same as metaplastic breast cancer. There are at least five known subtypes of MpBC.

MRI: A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. MRI is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging.

NOS:Not Otherwise Specified- This term is usually associated with a normal IDC Diagnosis. It’s sort of like saying this is plain old BC without any thing specifically unusual about it.

OS: Overall Survival is the rate at which you can expect to survive your cancer completely. Example: If you read that the five year overall survival rate for MpBC is 65% that means that at five years 65% of women have survived this cancer.

Pathology Report: A report is written each time tissue is removed from the body to check for cancer. These are called pathology reports. Each report has the results of the studies done on the removed tissue. The information in these reports will help you and your doctors decide on the best treatment for you. The pathology report is used by your doctor to determine which treatments are right for you.

PET scan: A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body. Also called positron emission tomography scan.

Progesterone: A type of hormone made by the body that plays a role in the menstrual cycle and pregnancy. Progesterone can also be made in the laboratory. It may be used as a type of birth control and to treat menstrual disorders, infertility, symptoms of menopause, and other conditions.

Prognosis Your prognosis is the anticipated outcome.

Radiation oncologist: A doctor who specializes in using radiation to treat cancer.

Radiation therapy: The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

Recurrence:When your tumor returns in or near the same location. A recurrence most likely occurs because some cancer cells remained after surgery.

Sarcoma: a malignant tumor arising in tissue of mesodermal origin (as connective tissue, bone, cartilage, or striated muscle) that spreads by extension into neighboring tissue or by way of the bloodstream

Systemic: Chemo is s systemic treatment which means it is delivered throughout your (system) whole body using the blood stream.

Sentinel lymph node biopsy: Removal and examination of the sentinel node(s) (the first lymph node(s) to which cancer cells are likely to spread from a primary tumor). To identify the sentinel lymph node(s), the surgeon injects a radioactive substance, blue dye, or both near the tumor. The surgeon then uses a scanner to find the sentinel lymph node(s) containing the radioactive substance or looks for the lymph node(s) stained with dye. The surgeon then removes the sentinel node(s) to check for the presence of cancer cells.

Spindle Cell: Spindle cell breast carcinoma is a rare sub-type of breast cancer, that falls within the general category of metaplastic breast carcinoma.

Squamous Cell: Squamous cell carcinoma is another subtype of metaplastic breast cancer. Very rarely is the squamous cell pure. often it is mixed with another kind of metaplastic carcinoma like spindle cell.

Stage:Often a patient will be given a “stage” for their cancer diagnosis. The stage is the extent of spread. Stage 0 means the tumor has not spread out of it’s original spot to invade other tissue. Stage 1 is a tumor that has invaded other tissue but is smaller than 2 CM. Stage two is a tumor that is over 2 CM but smaller than 5CM, Stage 3 is a tumor that exceeds 5 CM and stage 4 is a cancer that has spread to distant organs like the brain, lungs or liver.

Tamoxifen: A (hormone therapy) drug used to treat certain types of breast cancer in women and men. It is also used to prevent breast cancer in women who have had ductal carcinoma in situ (abnormal cells in the ducts of the breast). It has been approved to use as a “chemoprevention” in women who are at a high risk of developing breast cancer. It blocks the effects of the hormone estrogen in the breast but since metaplastic breast cancer is usually triple negative it is unlikely to be prescribed to an MpBC patient.

Targeted therapy: A type of treatment that uses drugs or other substances, such as monoclonal antibodies, to identify and attack specific cancer cells. Targeted therapy may have fewer side effects than other types of cancer treatments. However, very few targeted therapies exists at this time. Targeted therapy is the next phase for cancer treatments.

Triple-negative breast cancer:Most breast cancer is sensitive to the hormones estrogen and progesterone and the protein HER2. But breast cancer that tests negative for estrogen and progesterone receptors, and the HER2 protein is referred to as triple negative. Most (not all) metaplastic breast cancers are triple negative.

Whole Breast Radiation: A form of external beam radiation often given to breast cancer patients after surgery and/or chemo. The entire breast is given a low dose of radiation over a number of weeks. It is often done every day Mon-Fri for five to seven weeks.