Glossary of Terms

Introduction

Parts of this glossary have been taken or adapted from the National Cancer Institute’s Cancer Dictionary and the American Breast Cancer Society’s Breast Cancer Dictionary.

This glossary does not contain definitions of medications. To learn more about specific medications, visit the website of the National Cancer Institute.

Many thanks to the healthcare practitioners who reviewed portions of this glossary:

• Mechelle Barrick, RN, BSN, OCN, Greater Baltimore Medical Center
• Debra S. Copit, MD, Albert Einstein Medical Center
• Ann L. Honebrink, MD, Penn Health at Radnor
• Isabel I. Law, RN, South Carolina Comprehensive Breast Center
• Judith Macon, RN, MA, Suburban Hospital Cancer Program
• Suzanne McGettigan Bensman, MSN, CRNP, AOCN
• Lisa McGinty, RN, BSN, Abramson Cancer Center, University of Pennsylvania
• Maria Rocktashel, MSN, CRNP, Delaware Valley Surgical Associates
• Lynn M. Schuchter, MD, University of Pennsylvania Abramson Cancer Center
• Michele D. Stolper, Dana-Farber Cancer Institute
• Fionda N. Williams, RN, BSN, Baltimore City Cancer Program

Glossary

edema

Pronunciation: (eh-DEE-ma)

Swelling caused by excess fluid in body tissues.

efficacy

Effectiveness. In medicine, the ability of an intervention (for example, a medication or surgery) to produce the desired beneficial effect.

EGFR

Epidermal growth factor receptor. A protein found on the surface of some cells to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, including breast cancer cells, causing these tumor cells to divide excessively in the presence of epidermal growth factor. Also known as ErbB1 or HER1.

egg

Also called egg cell or ovum. The female reproductive cell.

egg freezing

A procedure in which the mature eggs harvested from the ovaries are removed and frozen for later use. Some women affected by breast cancer choose to harvest and freeze their eggs to protect them from potential damage resulting from breast cancer treatments.

egg harvesting

A procedure in which the ovaries are stimulated to mature several eggs, which are removed and frozen for later use. Some women affected by breast cancer choose to harvest and freeze their eggs to protect them from potential damage resulting from breast cancer treatments.

electroacupuncture

A procedure in which pulses of weak electrical current are sent through acupuncture needles into acupuncture points in the skin. The effectiveness of this procedure in the prevention of nausea and vomiting in people undergoing chemotherapy is being studied.

electron beam

A stream of electrons (small negatively charged particles found in atoms) that is used in radiation therapy.

electron microscope

A microscope (device used to magnify small objects) that uses electrons (instead of light) to produce an enlarged image. An electron microscope shows tiny details better than any other type of microscope.

electroporation therapy

EPT. A treatment that uses electrical pulses to stimulate an electrode that has been placed within the area of a tumor. The goal of EPT is to use the electrical pulses to enhance the ability of anticancer medications to enter tumor cells.

eligibility criteria

In clinical trials, this term refers to the requirements that must be met for an individual to be included in a study. These requirements help ensure that participants in a trial are similar to each other in terms of specific factors such as age, type and stage of breast cancer, general health, and previous treatment(s). When all participants meet the same eligibility criteria, it gives researchers greater confidence that results of the study are caused by the intervention being tested and not by other factors, including chance.

embolism

Pronunciation: (EM-bul-izm)

A block in an artery caused by blood clots or other substances, such as fat globules, infected tissue, or cancer cells.

embolization

Pronunciation: (EM-bo-lih-ZAY-shun)

The blocking of an artery by a clot or foreign material. Embolization can be performed as atreatment to block the flow of blood to a tumor.

embryo

The earliest stage in the development of a plant or an animal. In vertebrate animals (those that have a backbone or spinal column), this stage lasts from shortly after fertilization of an egg until all major body parts appear. In human beings, this stage lasts from about two weeks after fertilization until the end of the seventh or eighth week of pregnancy.

embryo freezing

A procedure in which the ovaries are stimulated to mature several eggs that are then removed and fertilized with sperm in the lab, creating embryos to freeze for later use. Some women affected by breast cancer choose to undergo this procedure to increase the chances of preserving their fertility after breast cancer treatments.

embryonic

Having to do with an embryo. This is an early stage in the development of a plant or animal.

emesis

A common medical term for vomiting.

emodin

A substance found in certain plants, including rhubarb. It belongs to a family of compounds called anthraquinones, which have shown anti-inflammatory and anticancer effects in early clinical research.

emotional response

An individual's emotions or feelings about a breast cancer diagnosis. These feelings may can change through time depending upon the person's diagnosis, treatment and psychological makeup.

encapsulated

Pronunciation: (en-KAP-soo-lay-ted)

Confined to a specific, localized area and surrounded by a thin layer of tissue.

endocrine

The internal secretion of substances (hormones) into the blood or lymphatic system. Many body organs secrete substances to regulate day-to-day bodily functions. Together these organs are referred to as the endocrine system.

endocrine therapy

Also called hormone therapy, hormonal therapy, or hormone treatment. A type of treatment that adds, blocks, or removes hormones from the body to slow or stop the growth of some types of breast cancers. Endocrine therapy may consist of synthetic hormones or other medications that block the body's natural hormones. Certain surgical procedures, such as removing a woman's ovaries, may also be a means to remove hormones from the body.

endocrinologist

Pronunciation: (en-do-krih-NAH-lo-jist)

A doctor who specializes in diagnosing and treating hormone- (or endocrine-) related disorders.

endogenous

Developing from or produced inside an organism or cell. The opposite is external (exogenous) production.

endometrial

Having to do with the endometrium (the layer of tissue that lines the uterus).

endometrial biopsy

A procedure in which a sample of tissue is taken from the endometrium (inner lining of the uterus) for examination under a microscope. A thin tube is inserted through the cervix into the uterus, and gentle scraping and suction are used to remove the sample.

endometrial disorder

Refers to any type of disorder relating to the endometrium, the layer of tissue that lines the uterus.

endometrial hyperplasia

An abnormal overgrowth of the endometrium (the layer of cells that lines the uterus). There are four types of endometrial hyperplasia: simple endometrial hyperplasia, complex endometrial hyperplasia, simple endometrial hyperplasia with atypia, and complex endometrial hyperplasia with atypia. These differ in terms of how abnormal the cells are and how likely it is that the condition will become cancerous.

endometriosis

Pronunciation: (en-do-mee-tree-O-sis)

A benign condition in which endometrial tissue grows in abnormal places outside the uterus but within the pelvic cavity, such as the ovaries or the bladder.

endometrium

Pronunciation: (en-do-MEE-tree-um)

The layer of tissue that lines the uterus.

endpoint

In clinical trials, an event or outcome that can be measured objectively to determine whether the intervention being studied is beneficial. The endpoints of a clinical trial are usually included in the study objectives. Some examples of endpoints are survival, improvements in quality of life, relief of symptoms, and disappearance of the breast tumor.

energy

Also called vital energy. Having the ability to take part in work or activity. Many women affected by breast cancer report changes in their energy level during and following treatment.

enteral nutrition

Also called tube feeding. A form of nutrition that is delivered into the digestive system as a liquid through a small feeding tube that empties into the stomach. People who are unable to meet their needs with food and beverages alone, and who do not have gastrointestinal problems like nausea, vomiting, or uncontrollable diarrhea, may be given tube feedings. Tube feeding can be used to meet or increase the nutritional needs of a person unable to take in enough nutrients on their own. A small feeding tube may be placed through the nose into the stomach or deeper into the small intestine, usually for short-term management of nutritional needs. A rube also may be surgically placed into the stomach or the intestinal tract through an opening made on the outside of the abdomen for longer-term nutritional management.

enzyme

A protein that speeds up or induces reactions in the body. For example, tumor cells secrete enzymes to allow them to grow more rapidly than normal cells.

eosinophil

A type of white blood cell that plays an active role in allergy responses.

eosinophilia

A condition in which the number of eosinophils (a type of white blood cell) in the blood is greatly increased. Eosinophilia is often a response to infection or allergens (substances that cause an allergic response).

epidemiology

The study of the patterns, causes, and control of disease in groups of people.

epidermal growth factor receptor

EGFR. A protein found on the surface of some cells to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, including breast cancer cells, causing these tumor cells to divide excessively in the presence of epidermal growth factor. Also known as ErbB1 or HER1.

epinephrine

Also called adrenaline. A hormone and neurotransmitter secreted in large amounts in response to fear and stress.

epithelial carcinoma

Pronunciation: (ep-ih-THEE-lee-ul kar-sin-O-ma)

Cancer that begins in the cells that line an organ (epithelial cells).

epithelial cell

Pronunciation: (ep-ih-THEE-lee-ul)

Refers to the cells that line the internal and external surfaces of the body that form the epithelium.

epithelial ovarian cancer

Pronunciation: (ep-ih-THEE-lee-ul)

Cancer that occurs in the cells lining the ovaries (epithelial cells of the ovary).

epithelium

Pronunciation: (EP-ih-THEE-lee-um)

A thin layer of tissue that covers organs, glands, and other structures within the body.

epitope

Pronunciation: (EP-i-tope)

A part of a molecule (or antigen) that an antibody will recognize and bind to.

EPT

Electroporation therapy. A treatment that uses electrical pulses to stimulate an electrode that has been placed within the area of a tumor. The goal of EPT is to use the electrical pulses to enhance the ability of anticancer medications to enter tumor cells.

ER

Estrogen receptor. A protein found on some breast cancer cells to which estrogen will attach.

ER+

Estrogen receptor positive. Breast cancer cells that have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER+ need the hormone estrogen to grow and will usually respond to hormone (antiestrogen) therapy that blocks these receptor sites.

ER-

Estrogen receptor negative. Breast cancer cells that do not have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER- do not need the hormone estrogen to grow and usually do not respond to hormone (antiestrogen) therapy that blocks these receptor sites.

ErbB1

A protein found on the surface of some cells to which epidermal growth factor binds, causing the cells to divide. It is found at abnormally high levels on the surface of many types of cancer cells, including breast cancer cells, causing these tumor cells to divide excessively in the presence of epidermal growth factor. Also known as EGFR or HER1.

erogenous zone

Parts of the body that, when touched or stimulated, arouse sexual feelings.

ERT

Estrogen replacement therapy. Hormones (estrogen, progesterone, or both) given to postmenopausal women or to women who have had their ovaries surgically removed. Hormones are given to replace the estrogen no longer produced by the ovaries.

erythema

Redness of the skin.

erythrocyte

Pronunciation: (eh-RITH-ro-site)

Also called a red blood cell (RBC). A cell that travels through the bloodstream and carries oxygen to all parts of the body.

estradiol

A form of the hormone estrogen that is produced by the ovaries.

estradiol level

The amount of the natural hormone estrogen circulating in a woman's body.

estrogen

The female sex hormone responsible for the development of secondary female sex characteristics, regulation of the menstrual cycle and embryo development.

estrogen receptor

Pronunciation: (ES-truh-jin)

A protein found inside the cells of the female reproductive tissue, some other types of tissue, and some breast cancer cells. The hormone estrogen will bind to the receptors inside the cells and may cause the cells to grow.

estrogen receptor negative

ER-. Breast cancer cells that do not have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER- do not need the hormone estrogen to grow and usually do not respond to hormone (antiestrogen) therapy that blocks these receptor sites.

estrogen receptor positive

ER+. Breast cancer cells that have a protein (receptor molecule) to which estrogen will attach. Breast cancer cells that are ER+ need the hormone estrogen to grow and will usually respond to hormone (antiestrogen) therapy that blocks these receptor sites.

estrogen receptor test

A lab test to determine if breast cancer cells have estrogen receptors. If the cells have estrogen receptors, these tumor cells may depend on estrogen for growth. This information may influence how the breast cancer is treated.

etiology

The study of factors that cause disease and how diseases originate.

evaluable disease

A term used in clinical trials that refers to tumors or disease that cannot be directly measured (cannot be measured by size). Malignant fluid in the abdomen, fluid in the lungs, and bone disease are examples of disease that can be assessed but not directly measured.

evaluable patients

People participating in a clinical trial whose response to treatments can be statistically reported because enough information has been collected about their response to treatment.

excision

Pronunciation: (ek-SI-zhun)

Removal by surgery, such as a tumor by cutting.

excisional biopsy

Pronunciation: (ek-SI-zhun-al BY-op-see)

A surgical procedure in which an entire lump or suspicious area is removed for evaluation. The tissue is then examined under a microscope for diagnosis.

expanded access trial

Also called compassionate use trial. A way to provide an investigational therapy to a person who is not eligible to receive that therapy in a clinical trial, but who has a serious or life-threatening illness for which other treatments are not available.

experimental

Also called investigational. In clinical trials, refers to a medication (including a new medicine, dose, combination, or route of administration) or procedure that has undergone basic testing and received approval from the U.S. Food and Drug Administration (FDA) to be tested in human beings. A medicine or procedure may be approved by the FDA for use in one disease or condition but be considered experimental in other diseases or conditions.

external radiation

Pronunciation: (ray-dee-AY-shun)

Also called external-beam radiation. Radiation therapy that uses a machine to aim high-energy rays topically at the breast cancer.

external-beam radiation

Pronunciation: (ray-dee-AY-shun)

Also called external radiation. Radiation therapy that uses a machine to aim high-energy rays topically at the breast cancer.

extract

Pronunciation: (EK-strakt)

In medicine, a concentrated preparation of a substance obtained from plants, animals, or bacteria and used as a medicine or in medications.

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