A person's chance of developing a specific disease over a specified time period. The absolute risk of disease is estimated by examining a large number of persons similar in some respect (in terms of age, for example) and counting the number of individuals in this group who develop the disease over the specified time period. For instance, if we were to observe 100,000 women between the ages of 20 and 29 for one year, approximately 4 would develop breast cancer during this period. Therefore, the one-year absolute risk of breast cancer for a 20- to 29-year-old woman is 4 per 100,000 women, or 1 per 25,000 women.
Use of fine needles inserted at precise points to influence "meridians" of energy flowing through the body and restore balance between yin and yang forces in the body. Acupressure and electroacupuncture are based on the same principle.
Adjuvant Systemic Therapy
Treatment given in addition to surgery and radiation to eliminate tumors that may have spread to other sites. There are two types, chemotherapy and hormone therapy.
Usually referring to aloe vera, a succulent perennial plant related to the lily family, often used to soothe burns and other skin irritations.
The absence or suppression of the menstrual period.
Loss of feeling or sensation. Local anesthesia may be induced into a specific region of the body, such as the breast, by injection of a drug (a local anesthetic) into that area. General anesthesia involves the entire body and may be induced by drugs injected into a vein or inhaled.
Aneuploid (DNA Ploidy)
The presence of an abnormal number of chromosomes in cancer cells.
Blood vessel formation, which usually accompanies the growth of malignant tissue.
A specially made antibody that targets cancer cells.
Referring to an agent that counteracts carcinogens (cancer causing agents).
Referring to an agent that counteracts oxidizing agents. Oxidizing agents are always present in the body and are often beneficial. However, when large amounts of oxidants are present in cells they can cause damage, especially to DNA, which can lead to cancerous growth.
A medicine to prevent or relieve nausea and vomiting.
A normal cellular process involving a genetically programmed series of events leading to the death of a cell.
The more darkly shaded circle of skin surrounding the nipple.
To remove fluid and a small number of cells.
Overgrowth of mildly abnormal but noncancerous (benign) cells within the breast milk ducts.
The underarm region.
Surgical procedure to remove lymph nodes from under the arm.
Axillary Lymph Nodes
The lymph nodes under the arm.
Axillary Sampling (axillary dissection)
Removal of some or all of the lymph nodes in the armpit.
"Life-knowledge," healing practice based on "doshas," biological principles that govern all bodily systems.
Not cancerous. Does not invade nearby tissue or spread to other parts of the body.
Benign Breast Disease
Noncancerous conditions of the breast that can result in lumps or abnormalities on a mammogram. Examples include fluid filled cysts and fibroadenomas.
See Prophylactic Mastectomy
A therapy that targets something specific to the biology of the cancer cell, as opposed to chemotherapy, which attacks all rapidly dividing cells. Often used to describe therapies that use the immune system to fight cancer (immunotherapy). Trastuzumab (Herceptin) is an example of a biological therapy agent.
Removal of tissue to be examined for cancer cells.
A test done to determine whether or not there are any signs of cancer in the bones. A small amount of radioactive material is injected into the bloodstream. It collects in the bones, especially abnormal areas, and is detected by a scanner. Collections on bone scan may result from cancer as well as from benign bone diseases like arthritis.
Additional dose of radiation to a reduced size radiation field.
An uncontrolled growth of abnormal breast cells.
Breast Conserving Surgery
Surgery that removes only part of the breast-the part containing and closely surrounding the cancerous tumor.
Breast Self-Examination (BSE)
A method used by women to become familiar with the normal appearance and feel of their breast tissue, so that if a change occurs it will be detected early.
Loss of appetite and weight experienced by many cancer patients.
Deposits of calcium in the breast that appear on a mammogram. Microcalcifications sometimes can indicate precancerous or cancerous cell growth.
General name for over 100 diseases in which cell growth is uncontrolled.
Carcinoma In Situ
Cancers contained in the milk ducts and lobules of the breast that have not left their original location and spread to the surrounding breast tissue. In situ means "in place."
An observational study that identifies two groups--one with people who already have the outcome of interest (cases), and one with people who do not (controls). The two groups are then compared to see if any characteristic was more prevalent in the past history of one group compared to the other.
One centigray describes the amount of radiation absorbed by the tissues and is equivalent to 1 RAD.
A drug or combination of drugs given in cycles. These drugs kill cancer cells in various ways.
Clinical Breast Examination (CBE)
The inspection and palpation of the breasts by a trained medical professional.
Research studies done with human patients. These studies generally test the benefits of possible new treatments or diagnostic procedures.
A study that follows a large group (a cohort) of people.
Complementary Therapies (CAM)
Forms of treatment that are used in addition to standard treatments. These practices are not considered standard medical approaches.
Computerized Axial Tomography (CAT) Scan
See CT Scan.
95% Confidence Interval
A statistical concept that indicates that there is a 95% probability that the 'true' measure of interest (for instance, the true relative risk relating alcohol consumption to breast cancer) is captured within an interval computed from a single study.
Core Needle Biopsy
A needle biopsy that removes pieces of tissue rather than just cells from an abnormal area in the breast.
Computed tomography scan. A series of pictures created by a computer linked to an X-ray machine. The scan provides detailed internal images of the body. Also called computerized tomography and computerized axial tomography (CAT) scan.
Summing of a person's risk for a disease up to a specified age. For example, it is commonly noted that the lifetime risk of breast cancer for an American woman born in 1990 is about 1 in 8 (or about 12%), if she lives to be 95. This means that for every 8 women who live to be age 95, one (or about 12%) will be diagnosed with breast cancer during her lifetime.
A fluid-filled sac.
A pathologist who specializes in looking at individual cells. A cytopathologist is needed to interpret the results of fine needle aspiration.
Toxic, or deadly, to cells (cell killing). Often used synonymously with chemotherapy.
When all of the known tumor is removed and no follow-up surgery is needed.
Concept prevalent in many special regimens, especially the Gerson diet, to indicate a process whereby the body is cleansed of unnatural, unhelpful or unhealthful agents, often taking the form of enemas.
Identification of a disease from its signs and symptoms.
A diagnostic mammogram is used to further evaluate a breast problem/symptom or an abnormal finding on a screening mammogram. This procedure involves two or more X-ray views per breast.
Diagnostic Radiologist (Radiologist)
A physician who specializes in the diagnosis of diseases by the use of X-rays.
Diploid (DNA Ploidy)
The presence of a normal number of chromosomes in cancer cells.
Return of cancer that has spread to other parts of the body, such as the lungs, liver or bone.
Chemotherapy given over a more condensed time period compared to standard therapy, such that the frequency of treatment sessions is increased, but the duration of the treatment period is shortened.
A chemotherapy drug that damages a cancer cell's ability to repair DNA.
A pathway in the breast through which milk passes from the lobules to the nipple (see figure).
Ductal Carcinoma In Situ (DCIS)
Type of in situ (non-invasive) breast cancer that originates mainly in the milk ducts of the breast.
A noncancerous breast tumor, arising in the breast duct, which usually cannot be felt. It generally appears as either a bloody or clear nipple discharge.
Early Breast Cancer
Cancer that is contained in the breast or has only spread to lymph nodes under the arm. The term is commonly associated with stage I and II cancer.
Endocrine Manipulation (Hormonal Therapy)
Treating breast cancer by changing the hormonal balance of the body instead of using cell-killing drugs.
The most biologically active naturally occurring estrogen in women.
A female hormone produced by the ovaries and adrenal glands. It is important to reproduction and may stimulate some cancers to grow.
See Hormone Receptors.
Surgical procedure that removes the entire suspicious area (plus some surrounding normal tissue) from the breast.
External Beam Radiation Therapy
See Radiation Therapy.
A test result that incorrectly reports that a person is disease-free when she/he actually has the disease.
A test result that incorrectly reports that a person has a disease when she/he does not have the disease.
A noncancerous breast change in which the breast responds to trauma with a firm, irregular mass, often years after the event. The mass is the result of fatty tissue dying, following either surgery or blunt trauma to the breast. This breast change is not associated with an increased risk of breast cancer.
A benign fibrous tumor that may occur at any age but is more common in young adulthood.
Fibrocystic Condition (Fibrocystic Changes)
A general term used to describe a noncancerous breast condition, sometimes resulting in painful cysts or lumpy breasts. Also referred to as benign breast disease [link to this glossary entry].
Fine Needle Aspiration (FNA)
Biopsy procedure that uses a very thin, hollow needle to remove a sample of cells from the abnormal area of the breast. Also called a fine needle biopsy.
A laboratory test performed on malignant breast tissue to determine the growth rate of malignant cells and the presence of abnormal chromosomes.
Fluorescence in situ hybridization (FISH)
A laboratory test performed on breast tumor tissue to detect the number of copies of the HER2/neu gene in the cancer cells.
Process where a portion of tissue from a surgical biopsy is frozen so that a thin slice can be quickly cut and analyzed to see if it is cancerous or not. Frozen section results are only preliminary and always need to be confirmed by other methods.
Milk filled cyst.
The part of a person's cells that contains all the DNA information that determines how they will grow and develop, and how their body works. The information in a person's genes is inherited from previous generations on both sides of a person's family.
A 'mistake' or 'alteration' of the information contained in a gene.
General Practitioner/Internist (Physician)
A woman's personal or family physician who may first detect a suspicious area through a clinical breast exam or abnormal mammogram.
Protein that appears in high numbers on the outside of the breast cancer cells of about 20 to 25 percent of breast cancer patients. Tumors with high levels of HER2/neu are effective targets for the biological therapy drug, trastuzumab (Herceptin).
Chemicals produced by various glands in the body, which produce specific effects on specific target organs and tissues.
Specific proteins on breast cells that hormones attach to. A high number of hormone receptors often indicates that a cancer cell needs the hormone to grow.
Indicator of a breast cancer's need for hormones to grow. A hormone-receptor positive cancer needs hormones to grow. A hormone-receptor negative cancer does not need hormones to grow. See Hormone Receptor.
Treatment that works by keeping cancer cells from getting the hormones they need to grow.
See Biological Therapy.
A laboratory test performed on tumor tissue to detect the amount of a specific genetic protein in the cancer calls.
An "envelope" containing silicone, saline or both, used to restore breast form.
The number of new cases of a disease that develop in a specific time period.
Surgical biopsy that removes only part of the tumor, usually done on advanced or large tumors.
Prepayment insurance plan providing services or cash indemnities for medical care needed in times of illness or disability.
Induction Chemotherapy (Primary Chemotherapy, Preoperative Chemotherapy or Neoadjuvant Therapy)
Chemotherapy used as a first treatment, often used for large or advanced cancers to shrink tumors before surgery.
Informed Consent (risks and benefits)
The process through which a patient learns about the possible benefits and side effects of a recommended treatment plan and then accepts or declines the treatment. The patient is usually asked to sign a consent document, and may decide to stop the treatment at any time and receive other available medical care.
In Situ Cancer
See Carcinoma In Situ.
See Complementary Therapy.
Within the milk duct. Intraductal can describe a benign or malignant process.
An excess of cells growing within the breast's milk ducts.
Being within or entering the body by way of the veins.
Cancer that has spread from the original location into the surrounding breast tissue and possibly into the lymph nodes and other parts of the body.
Investigational New Drug (new experimental treatment)
A chemical or biological drug that has been approved for use by clinical investigators in research trials but which is not yet available for commercial use.
Complementary therapy derived from mistletoe that some believe may help stimulate the immune system and kill cancer cells.
The process of producing milk and breastfeeding a child.
Substance produced as waste by cancer cell metabolism.
Large Veins (Deep Veins)
The large veins deep inside the legs that carry blood from the lower limbs back to the heart.
Area of abnormal tissue.
The device used during radiation therapy to direct X-rays into the body.
An image of the liver that can show the presence or absence of a tumor. Radioisotope tracer is injected into the blood stream. This tracer will travel to the liver and collect there, especially in abnormal places that can be detected by a scanner.
Lobular Carcinoma In Situ (LCIS)
A type of carcinoma in situ where the cells originate mainly in the lobules of the breast.
Lobular Neoplasia In Situ
See Lobular Carcinoma In Situ.
Spherical-shaped sacs in the breast that produce milk.
Anesthesia that only numbs the cells in a specific area.
Treatment that focuses on getting rid of the cancer from a limited (local) area. In breast cancer, this would be the breast, the chest wall and lymph nodes in the armpit (axillary nodes).
Localized Breast Cancer
Cancer that is contained in the breast and has not spread to surrounding tissue, lymph nodes or other organs.
Locally Advanced Breast Cancer
Cancer that has spread beyond the breast to the skin or chest wall, but not to distant organs like the lungs and liver. The term is commonly associated with stage III cancer. It also refers to a tumor that is > 5 cm (about 2 inches) in size.
Any kind of mass in the breast or elsewhere in the body.
See Breast Conserving Surgery.
The network of lymph nodes and vessels throughout the body.
The swelling of the arm due to poor draining of lymph fluid that can occur after surgery to remove lymph nodes or after radiation therapy to the area.
Lymph Nodes (Lymph Glands)
Small clumps of immune cells that act as filters for the lymphatic system. Clusters of lymph nodes are found in the underarms, groin, neck, chest and abdomen.
Lymph Node Status
Indicator of whether or not cancer has spread to the lymph nodes. Lymph node-positive means that cancer has spread to the lymph nodes. Lymph node-negative means that cancer has NOT spread to the lymph nodes. See Lymph Nodes.
Complementary dietary therapy based on the ancient Eastern concepts of yin and yang. It encourages largely vegetarian, organic foods and defines specific methods of preparation.
Mammary Duct Ectasia
A noncancerous breast condition resulting from the inflammation and enlargement of the ducts behind the nipple. Generally women do not experience any symptoms, however, calcifications seen on a mammogram may indicate its presence. No treatment is necessary if the woman is not experiencing any symptoms (burning, pain or itching of the nipple area).
The breast glands that produce and carry milk, by way of ducts, to the nipples during pregnancy.
An X-ray of the breast.
The area of normal tissue surrounding the cancerous tumor after it has been removed during surgery. A margin is clean (also known as uninvolved or negative) if there is only normal tissue (and no cancer cells) at the edges of the tissue removed. Clean margins indicate that the entire tumor was removed. With involved (also known as positive) margins, normal tissue does not completely surround the tumor, and therefore the entire tumor was not removed.
Surgical removal of the breast. The exact procedure depends on the patient's diagnosis. See Total Mastectomy and Modifed Radical Mastectomy.
An inflammation of the breast usually occurring during lactation. Symptoms include pain, nipple discharge, fever and redness and/or hardness over an area of the breast.
Hormone produced by the pineal gland in the brain, an important part of the body's internal timing system.
The first menstrual period.
The ending of the normal menstrual cycle in women. It occurs most frequently in the late forties or early fifties.
A method for taking the results reported in a group of studies and 'averaging' them in a certain way to come up with a single, summary result.
The chemical process whereby drugs and food are broken down by the body.
Spread of the cancer to other organs through the lymphatic and/or circulatory system.
Small, clustered deposits of calcium in the breast, which may be seen on a mammogram. These may or may not be associated with a breast lump. Approximately 20 to 25 percent represent breast cancer.
Modified Radical Mastectomy
Surgical removal of the breast, the lining of the chest muscles and some of the lymph nodes in the armpit. Used to treat early and locally advanced breast cancer.
Immune proteins that can locate and bind to cancer cells wherever they are in the body. They can be used alone, or they can be used to deliver drugs, toxins or radioactive material directly to tumor cells. Trastuzumab (Herceptin) is an example of a monoclonal antibody used to treat breast cancer.
MRI (Magnetic Resonance Imaging)
An imaging technique that uses a magnet linked to a computer to create detailed pictures of parts of the body like the liver, brain, lung, chest or any other organ suspected of having cancer.
Use of two or more treatment methods (i.e., surgery, radiation therapy, chemotherapy, immunotherapy) in combination or sequentially to achieve optimal results.
See Gene Mutation.
Insertion of a very thin wire into an abnormal area of the breast, used to highlight the location of a nonpalpable lesion so that it can be removed during open biopsy or breast conserving surgery.
See Induction Chemotherapy.
Excessive number of cells in a mass that can be either benign or malignant.
Nested Case-control Study
A case-control study performed within a prospective cohort study. The major advantage of a nested case-control study over a regular case-control study is that the exposure measures of interest (for example, diet or alcohol use) are obtained before any of the participants developed disease, making them less subject to bias.
Breast lump or abnormality that cannot be felt but that can be detected on a mammogram.
A research study where participants live their daily lives as usual and report their activities to researchers.
Quantitative measure reported in case-control studies that describes the increase (or decrease) in risk associated with a specific risk factor. An odds ratio is interpreted in the same way as a relative risk, though it is calculated differently.
The doctor who is responsible for planning and overseeing treatment of cancer.
A physician specializing in the treatment of cancer using chemotherapy and hormonal therapy.
A physician specializing in the treatment of cancer using high energy X-rays.
A physician specializing in the treatment of cancer using surgical procedures.
A method for diagnosis and treatment of breast cancer. The biopsy is performed under general anesthesia. If cancer is confirmed by frozen section examination, a surgeon will then proceed with definitive surgical treatment. It should be noted that this is no longer the standard procedure unless the woman is informed and consents in advance to a one-step procedure.
Surgical removal of the ovaries.
Palliative Therapy (Palliation)
A treatment that may relieve symptoms (like pain) without curing the disease.
Breast lumps or abnormalities that can be felt during a clinical breast examination.
To examine, using the hands and fingers.
Partial Mastectomy (Breast Conserving Therapy, Lumpectomy, Wide Excision, or Excisional Biopsy)
Surgery that removes only the part of the breast containing and closely surrounding the cancer tumor.
The doctor who microscopically evaluates the breast tissue and lymph nodes removed during biopsy or surgery.
A method used for final tissue diagnosis. After overnight tissue processing, thin slices of tissue are mounted on a slide and examined microscopically by a pathologist. These sections are of better quality than the frozen section, and are used for final pathological diagnosis. It generally takes three working days to receive this final report.
A part of the brain that regulates growth and other glands in the body, such as the ovaries.
A method for collecting all the individual data from a group of studies, combining them into one large set of data, and then analyzing the data as if it came from one big study.
Factors, such as hormone receptor status, which help predict the kind of treatment that will be most effective for a specific cancer case.
To make more susceptible to a disease.
Women who have regular periods.
See Induction Chemotherapy.
The proportion (percentage) of individuals in a population who have a particular disease, behavior or characteristic at a specified point in time.
The elimination of causes of disease from the population, so that risk of disease is either eliminated (as in the case of many infectious diseases today), or postponed until later in life (with heart disease and various cancers).
See Induction Chemotherapy.
The original cancer in the breast.
The expected or probable outcome or course of a disease; the chance of recovery.
Factors-such as tumor type, size and grade-that help to determine a woman's prognosis.
An antiestrogenic steroid used to correct abnormalities of the menstrual cycle, as a contraceptive, and to control habitual abortion. See Hormone Receptor.
See Hormone Receptor.
Rapidly growing and increasing in number.
Preventive surgery where one breast or both breasts are removed in order to keep cancer from developing. When both breasts are removed, the procedure is called bilateral prophylactic mastectomy.
An observational study that follows people forward in time.
See Cohort Study
An artificial breast form that can be worn under clothing after a mastectomy.
An outline or plan for use of an experimental drug, treatment or procedure in cancer therapy or diagnosis.
Surgery where one quadrant or 25% of the breast is removed. See Breast Conserving Surgery.
Categories of an exposure based on equal divisions of the total number of people in the study. When the total number of people is divided into thirds, the categories are called tertiles. When the total number of people is divided into quarters, the categories are called quartiles.
RAD (dose of radiation)
Abbreviation for "radiation absorbed dose." This term describes the amount of radiation absorbed by the tissues. One RAD is equal to one centigray. See Centigray.
Radiation Therapy (Radiotherapy)
Treatment given by a radiation oncologist using moderate-dose radiation to kill or damage cancer cells in the area exposed.
Radical Mastectomy (Halsted Radical)<br> Surgical removal of the breast, chest muscles and underarm lymph nodes. Procedure has been replaced by less extensive mastectomy procedures.
The radiologist oversees and reads any X-rays, mammograms or other scans related to diagnosis or follow-up. In general, radiologists specialize in creating and interpreting pictures of areas inside the body. Radiologists also perform needle biopsy and wire localization procedures.
See Radiation Therapy.
Randomized Controlled Trials
Studies where researchers intervene to change some participants' behavior or to provide a particular therapy to see how it affects their health. These studies are called randomized controlled trials because the participants are randomly assigned (as if by coin toss) to either an intervention group (such as one taking a chemoprevention drug) or a control group (such as one taking an inactive placebo).
A way to recreate the breast's shape after a natural breast has been removed. Various procedures are available, some of which involve the use of implants. May also be referred to as reconstruction mammoplasty.
Return of cancer. Local recurrence is the return of cancer to the same breast or chest wall. Distant recurrence is the return of cancer to another location, such as the lungs or liver. See Metastases.
The shrinking of a tumor.
Quantitative measure used to describe the increase (or decrease) in risk associated with a specific risk factor. A relative risk is the ratio of two absolute risks: the numerator is the absolute risk among those with the risk factor, while the denominator is the absolute risk among those without the risk factor.
A temporary or permanent disappearance of the signs and symptoms of cancer.
Risk (of Disease)
Probability of disease developing in an individual during a specified time period.
The relationship between the possible (or expected) side effects and benefits of a recommended treatment or procedure.
Any factor-from a lifestyle choice (such as diet) to genetic make-up to an environmental exposure (such as radiation)-that increases or decreases a person's risk of developing a certain disease.
The different combinations and timing for chemotherapy and other drugs.
A test or procedure used to detect cancer or a pre-cancerous condition in an apparently healthy person without symptoms.
Screening mammography is used to identify early signs of breast cancer in a woman who is not currently having any breast problems or symptoms. This procedure involves two X-rays views of each breast.
Second Primary Tumor
A second breast cancer that arises in a different location from the first. Different from a local recurrence, which is the return of the first breast cancer.
In relation to a summary table, the specific standards (such as study design and number of participants) that a study has to meet to be included in a table.
The proportion (or percentage) of people who truly have the condition of interest who 'test positive' for that condition.
Sentinel Node Biopsy
The surgical removal and examination of the sentinel node (first node filtering lymph fluid from the tumor site) to see if the node contains cancer cells.
Medical-grade silicone rubber gel, which is similar to the consistency of the normal breast.
See Total Mastectomy.
Simulator (for Radiation Therapy)
A clinical X-ray unit used to define the exact treatment area for radiation therapy.
Examination of cancer cells to see how many are in the process of dividing DNA at any one time.
The proportion (or percentage) of people who truly do NOT have the condition of interest who 'test negative' for that condition.
Performing exams and tests to learn the extent of the cancer within the body-its stage. Knowing a cancer's stage helps determine what treatment is necessary and how effective this treatment may be in getting rid of the disease and prolonging life.
The usual treatment currently in widespread use and considered to be of proven effectiveness on the basis of previous experience.
A statistical concept indicating that the result of a study is very unlikely due to chance and, therefore, likely represents a true relationship between a risk factor and a disease of interest.
Stereotactic Needle Biopsy
Core needle biopsy performed with the use of stereotactic mammography.
Three-dimensional mammography used when taking a needle biopsy of a breast abnormality that can't be felt.
Doctor who performs any surgery related to breast cancer, including surgical biopsies.
Treatment of the whole body with substances that travel through the bloodstream and affect cancer cells all over the body.
Drug that is used to treat both early and advanced stage breast cancer. Taken in pill form, tamoxifen works by blocking the hormone estrogen from cancer cells that are estrogen receptor-positive, therefore preventing their growth.
Drug therapies designed to attack specific molecular agents or pathways involved in the development of cancer.
Complementary therapy where trained practitioners enter a semi-meditative state and hold their hands just above the body to sense energy imbalances due to illness. Healing energy is then said to transfer to the patient.
Total Mastectomy (Simple Mastectomy)
Surgical removal of the breast but no other tissue or nodes. Used for the treatment of ductal carcinoma in situ and, in some instances, recurrent breast cancer. Also the procedure used in prophylactic mastectomy.
An abnormal growth or mass of tissue that may be benign (noncancerous) or malignant (cancerous).
Describes how closely a cancer resembles normal tissue. The higher the grade, the less it resembles normal tissue, and the faster the cancer's rate of growth is likely to be.
Biopsy and further surgical treatment performed at two separate times.
Diagnostic test that uses sound waves to create images of tissues and organs. Tissues of different densities reflect sound waves differently.
This surgical procedure involves the removal of a portion of the breast tissue, however, the amount is not specified. It is important that the woman clarify with her surgeon the extent of breast tissue removal. See Breast Conserving Surgery.
See Needle Localization.
Radiation that can be useful, at low levels, in the diagnosis of cancer and, at high levels, in its treatment.
*Parts of this glossary were adapted from the National Cancer Institute's "Cancer Definitions" and "Cancer.gov Dictionary".
**Glossary terms relating to radiation therapy adapted from the "Glossary of Terms" from the Joint Center for Radiation Therapy website.