Breast Cancer Genetics Network of Michigan Definitions

Contents

DEFINITIONS

Chemoprevention

Clinical Breast Exam (CBE)

Deoxyribonucleic Acid (DNA)

Ductal Carcinoma In Situ (DCIS)

Genetic Information

Hormone Replacement Therapy (HRT)

Insurance Provider

Lobular Carcinoma In Situ (LCIS)

BRCA1
A common abbreviation for BReast CAncer gene 1; a gene discovered in 1994. All humans have the gene BRCA1, however mutations that cause the gene to work improperly can be inherited or can occur sporadically. Mutations in this gene, located on chromosome 17q21, are associated with a higher risk of certain gene of cancer such as breast (female), ovarian, colon and prostate.
See also: Chromosome, Gene, Mutation

BRCA2
A common abbreviation for BReast CAncer gene 2; a gene discovered in 1995. All humans have the gene BRCA2, however mutations that cause the gene to work improperly can be inherited or can occur sporadically. Mutations in this gene, located on chromosome 13q-12-13, are associated with a higher risk of certain types of cancer such as breast (female and male), ovarian, pancreas, gastrointestinal tract, and prostate.
See also: Chromosome, Gene, Mutation

Biopsy
A biopsy is a procedure that involves extracting cells (via a needle or incision) for closer examination under a microscope. These are performed to make the most precise diagnosis of a tissue condition.
See also: Cell

Cancer
A general name for the condition in which abnormal cells grow in an uncontrolled manner. Cancer can invade and destroy healthy tissues and spread via the bloodstream and lymphatic system to other parts of the body.
See also: Cell

Cell
In biology, the word cell refers to the small building blocks that make up all of the tissues and organs of the body. Cells contain chromosomes that store the hereditary information (DNA).
See also: Chromosome, DNA

Chemoprevention
Chemoprevention is a process by which a substance, natural or man-made, is used to try to prevent cancer. Substances used in chemoprevention try to stop normal cells from turning into cancer cells and to block damaged cells from multiplying. Unlike chemotherapy (which is given to stop the progression of an already existing cancer), chemoprevention is administered to healthy individuals who are typically at increased risk, to try to prevent a new diagnosis of cancer.
See also: Cancer, Cell

Chromosome
Chromosomes are composed of hereditary material (DNA). Almost every human cell has 46 chromosomes arranged in 23 pairs. Each parent contributes one chromosome to each pair, so children get half of their chromosomes from their mothers and half from their fathers.
See also: Cell, Chromosome

Clinical Breast Exam (CBE)
A physical examination of the breasts, underarms, and collarbone area conducted by a doctor, nurse, or other certified health professional.

Deletion
The total loss (or absence) of nucleotide(s). Nucleotide deletion plays a role in birth defects and in the development of cancer. For example, 185delAG is a common mutation of the BRCA1 gene where the nucleotide A and G are deleted from position 185.
See also: BRCA1, Mutation, Nucleotide

Deoxyribonucleic Acid (DNA)
Found inside the nucleus of the cell, DNA is the molecule that encodes genetic information. It determines the structure, function and behavior of the cell. DNA is often illustrated as a double helix "spiral ladder" with nucleotides making the rungs. The four nucleotides in DNA are the bases: adenine (A), guanine (G), cytosine (C), and thymine (T). DNA is what is replicated and passed on from generation to generation as "hereditary information."
See also: Cell, Genetic Information, Nucleotide

Ductal Carcinoma In Situ (DCIS)
Ductal Carcinoma In Situ (DCIS) is an alteration of cells that is associated with an increased risk for the development of an invasive breast cancer. DCIS itself is not invasive and lacks the ability to metastasize (spread). DCIS does not usually form a breast lump so it typically cannot be detected by breast examinations. Sometimes calcifications occur at or near the DCIS, which can be detected by a mammogram. These calcifications develop when some of the cells die, causing changes in the environment (pH) of the breast tissue. Because of the change in the environment (pH), calcium salts from the blood are deposited in the area of the DCIS. When calcifications are found in a group, or form branching patterns, a breast biopsy may be ordered to determine whether DCIS or invasive disease is present. In many cases, however, when calcifications are removed, no DCIS is found.

The chance of finding invasive cancer appears to be related to the extent and type of DCIS found. Once DCIS is found, there is an increased risk for developing invasive breast cancer at that location. As the extent of DCIS in the breast increases so does the risk for developing invasive breast cancer in one of these areas.
See also: Biopsy, Cancer, Cell, Mammogram

Estrogen
Estrogen is a naturally occurring hormone that exerts its effects throughout the body. Estrogen is particularly well studied due to its involvement in the female reproductive functions such as puberty, ovulation, pregnancy and menstruation (periods). After menopause estrogen supplements are often taken as a part of hormone replacement therapy (HRT).
See also: HRT, Hormone

Gene
The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain information for making a specific protein.
See also: DNA

Genetic Information
Information about gene, gene products, or inherited characteristics that may derive from the individual or a family member. This includes your biological family's medical history.
See also: Gene

Genetic Test
A test utilized to search DNA for mutations.
See also: DNA, Mutation

Hormone Replacement Therapy (HRT)
Medication containing hormones that are taken to offset the symptoms and other effects of loss. These effects often accompany aging, menopause, and other syndromes associated with low or absent hormone levels.
See also: Hormone

Hormone
A naturally occurring substance produced by the body. When carried via the bloodstream to their target site, they affect the metabolism or behavior of other cells.
See also: Cell

Hyperplasia
The abnormal multiplication or increase in the number of normal cells. Several types of benign breast conditions involve hyperplasia.
See also: Cell

Insertion
The addition of nucleotide(s). Nucleotide insertion can play a role in birth defects and in the development of cancer. For example, 5382insC is a common mutation of the BRCA1 gene where the nucleotide C is inserted at position 5382.
See also: BRCA1, Mutation, Nucleotide

Insurance Provider
An insurance company, employer, or any other entity providing a plan of health insurance or health benefits including group and individual health plans whether fully insured or self-funded.

Lobular Carcinoma In Situ (LCIS)
Lobular Carcinoma In Situ (LCIS) is a noninvasive cell change associated with an increased risk for developing invasive breast cancer. LCIS does not have the ability to metastasize (spread) and is not itself a cancer. LCIS itself does not form a lump nor is it visible on mammogram. It is a diagnosis made by a pathologist after a breast biopsy (usually done for other concerns). Therefore, it is likely that LCIS remains undetected in many women who have never had a biopsy or who had a part of the breast biopsied that did not show signs of LCIS.

The typical patient with LCIS learns that she has 18-20% lifetime risk for developing an invasive cancer. Both breasts share this risk equally, even if LCIS is found in only one breast. The cells making up the LCIS lesion do not themselves usually develop into invasive cancer cells, but the presence of LCIS increases the risk for an invasive cancer anywhere in either breast.
See also: Biopsy, Cancer, Cell, Mammogram

Mammogram
A special imaging examination of the breast using X-rays. The purpose of this test is to detect breast cancer early when lumps are less than 2 cm or smaller in size (most lumps are not felt by the hand when they are 1 cm or less in diameter).

Menopause
The time when a woman's monthly menstrual periods cease. This can be accompanied by a decrease in hormone levels.
See also: Hormone

Mutation
A permanent structural alteration in DNA. Some alterations have no effect or harm, but make us, as humans, to be unique individuals. Other alterations can confuse or garble DNA instructions inhibiting the body to perform tasks in their typical manner.
See also: DNA

Nucleotide
The bases adenine (A), guanine (G), cytosine (C), and thymine (T) are collectively called nucleotides. In DNA, pairs of bases join together with specific partners (A with T and C with G) to form the "rungs" of the molecule's "spiral ladder" structure. Changes in the arrangement of these nucleotides can cause mutations to occur in the cell and may have negative effects on the body.
See also: DNA, Mutation

Nucleus
The central cell structure that houses the chromosomes.
See also: Cell, Chromosome

Prophylactic
Surgery to remove non-cancerous tissue(s) or organ(s) for the purpose of reducing an individual's cancer risk. It can be considered a preventive measure.

Raloxifene
Raloxifene is a drug that is currently used to help prevent and treat osteoporosis (weakening of the bones) in post-menopausal women. Scientists believe that raloxifene may have potential benefits in the prevention of breast cancer, and are currently testing the effectiveness of the drug for chemoprevention.
See also: Cancer, Chemoprevention, Menopause

Tamoxifen
A hormonally related drug that has been used to treat and reduce the risk of breast cancer.
See also: Hormone

BREAST CANCER GENETICS NETWORK OF MICHIGAN
7217 CCGC, Box 0948 1500 East Medical Center Drive Ann Arbor MI 48109-0948
CONTACT INFORMATION