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Rhabdomyosarcoma, Childhood

Rhabdomyosarcoma, Childhood: Glossary of Cancer

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A
Abdomen   
The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.
 
Acute  
Symptoms or signs that begin and worsen quickly; not chronic.
  
Advanced cancer 
Cancer that has spread to other places in the body and usually cannot be cured or controlled with treatment.
 
Adjuvant Therapy 
Treatment given after the primary treatment to increase the chances of a cure. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, or biological therapy.
 
Aggressive  
A quickly growing cancer.
 
AIDS   
Acquired immunodeficiency syndrome. A disease caused by human immunodeficiency virus (HIV). People with AIDS are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called acquired immunodeficiency syndrome.  
 
AIDS-Related Cancer   
Certain cancer types that are more likely to occur in people who are infected with the human immunodeficiency virus (HIV). The most common types are Kaposi’s sarcoma and non-Hodgkin’s lymphoma. Other AIDS-related cancers include Hodgkin’s disease and cancers of the lung, mouth, cervix, and digestive system.
 
Alopecia  (al-oh-PEE-shuh)
The lack or loss of hair from areas of the body where hair is usually found. Alopecia can be a side effect of some cancer treatments.
 
American Cancer Society 
The American Cancer Society is the nationwide community-based voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer, through research, education, advocacy, and service.

 Video  John Seffrin, PhD., American Cancer Society, “Access to Care”

 
Androgen-independent  
Describes the ability of tumor cells to grow in the absence of androgens (hormones that promote the development and maintenance of male sex characteristics). Many early prostate cancers require androgens for growth, but advanced prostate cancers are often androgen-independent.
 
Anemia 
A condition in which the number of red blood cells is below normal.
  
Anesthesia  
Drugs or substances that cause loss of feeling or awareness. Local anesthetics cause loss of feeling in a part of the body. General anesthetics put the person to sleep.
 
Anesthesiologist (a-nes-THEE-zee-AH-loh-jist)
A doctor who specializes in giving drugs or other agents to prevent or relieve pain during surgery or other procedures being done in the hospital.
 
Antagonist   
In medicine, a substance that stops the action or effect of another substance. For example, a drug that blocks the stimulating effect of estrogen on a tumor cell is called an estrogen receptor antagonist.
 
Antibody therapy 
Treatment with an antibody, a substance that can directly kill specific tumor cells or stimulate the immune system to kill tumor cells.
 
Anticancer Antibiotic  
A type of anticancer drug that blocks cell growth by interfering with DNA, the genetic material in cells. Also called an antitumor antibiotic or antineoplastic antibiotic.
  
Anticarcinogenic 
Having to do with preventing or delaying the development of cancer.
 
Antihormone therapy 
Treatment with drugs, surgery, or radiation in order to block the production or action of a hormone. Antihormone therapy may be used in cancer treatment because certain hormones are able to stimulate the growth of some types of tumors.
 
Antioxidant  
A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, vitamins A, C, and E, and other natural and manufactured substances.
 
 
B
 
B cell  
A white blood cell that comes from bone marrow. As part of the immune system, B cells make antibodies and help fight infections. Also called B lymphocyte.
 
Basal Cell Carcinoma 
A type of skin cancer that arises from the basal cells, small round cells found in the lower part (or base) of the epidermis, the outer layer of the skin.
Basel Cell Carcinoma (See Basal Cell Carcinoma above)
 
Biologic therapy
Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
 
Bone Marrow
Blood cells form in the bone marrow. Bone marrow is the soft material in the center of most bones. The bone marrow makes different types of blood cells. Each type has a special function:
  • White blood cells help fight infection.   
  • Red blood cells carry oxygen to tissues throughout the body.   
  • Platelets help form blood clots that control bleeding.

Benign

Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body.

 
Beta Carotene 
A substance found in yellow and orange fruits and vegetables and in dark green, leafy vegetables. The body can make vitamin A from beta carotene. Beta carotene is being studied in the prevention of some types of cancer. It is a type of antioxidant.
 
Bilateral Cancer    
Cancer that occurs in both paired organs, such as both breasts or both ovaries.
 
Biopsy 
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. When only a sample of tissue is removed, the procedure is called an incisional biopsy. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. When a sample of tissue or fluid is removed with a needle, the procedure is called a needle biopsy, core biopsy, or fine-needle aspiration.
 
Cancer that forms in tissues of the bladder (the organ that stores urine). Most bladder cancers are transitional cell carcinomas (cancer that begins in cells that normally make up the inner lining of the bladder). Other types include squamous cell carcinoma (cancer that begins in thin, flat cells) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). The cells that form squamous cell carcinoma and adenocarcinoma develop in the inner lining of the bladder as a result of chronic irritation and inflammation.
 
Blast
An immature blood cell.
 
Bone Marrow
The soft, sponge-like tissue in the center of most bones. It produces white blood cells, red blood cells, and platelets.
 
Bone Cancer
Primary bone cancer is cancer that forms in cells of the bone. Some types of primary bone cancer are osteosarcoma, Ewing sarcoma, malignant fibrous histiocytoma, and chondrosarcoma. Secondary bone cancer is cancer that spreads to the bone from another part of the body (such as the prostate, breast, or lung).
 
Bone Scan
A technique to create images of bones on a computer screen or on film. A small amount of radioactive material is injected into a blood vessel and travels through the bloodstream; it collects in the bones and is detected by a scanner.
 
BPH
Benign prostatic hypertrophy. A benign (noncancerous) condition in which an overgrowth of prostate tissue pushes against the urethra and the bladder, blocking the flow of urine. Also called benign prostatic hypertrophy and benign prostatic hyperplasia.
 
 
BRM Therapy
Biological response modifier therapy. Treatment to boost or restore the ability of the immune system to fight cancer, infections, and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Agents used in BRM therapy include monoclonal antibodies, growth factors, and vaccines. These agents may also have a direct antitumor effect. Also called immunotherapy, biological therapy, biotherapy, and biological response modifier therapy.
 
 
C
 
C cell
A type of cell in the thyroid. C cells make calcitonin, a hormone that helps control the calcium level in the blood.
 
Carcinogen
Any substance that causes cancer.
 
Carcinoma
Cancer that begins in the skin or in tissues that line or cover internal organs.
 
Carcinoma in Situ
A group of abnormal cells that remain in the tissue in which they first formed. These abnormal cells may become cancer and spread into nearby normal tissue.
 
Chemotherapy
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
 
 
Chondrosarcoma
A type of cancer that forms in cartilage.
 
Chromosome
Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.
 
Chronic
A disease or condition that persists or progresses over a long period of time.
 
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 a clinical study.
 
Cohort Study
A research study that compares a particular outcome (such as lung cancer) in groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke compared with those who do not smoke).
 
 
Concurrent Therapy
A treatment that is given at the same time as another.
 
 
D
 
De Novo
In cancer, the first occurrence of cancer in the body.
 
Depression
A mental condition marked by ongoing feelings of sadness, despair, loss of energy, and difficulty dealing with normal daily life. Other symptoms of depression include feelings of worthlessness and hopelessness, loss of pleasure in activities, changes in eating or sleeping habits, and thoughts of death or suicide. Depression can affect anyone, and can be successfully treated. Depression affects 15-25% of cancer patients.
 
Dermatologist
A doctor who has special training to diagnose and treat skin problems.
 
Diagnosis
The process of identifying a disease by the signs and symptoms.
 
Duct
In medicine, a tube or vessel of the body through which fluids pass.
 
Ductal Carcinoma
The most common type of breast cancer. It begins in the cells that line the milk ducts in the breast.
 
Ductal Carcinoma In Situ
DCIS. 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. Also called DCIS and intraductal carcinoma.

 
E
 
Early Menopause
A condition in which the ovaries stop working before age 40. Symptoms include hot flashes, mood swings, night sweats, vaginal dryness, and infertility. Some cancer treatments, such as chemotherapy, radiation therapy, and surgery can cause early menopause. This may be temporary or permanent and may be treated with hormone replacement therapy. Also called premature ovarian failure or primary ovarian insufficiency.
 
Electrolyte
A substance that breaks up into ions (electrically charged particles) when it is dissolved in body fluids or water. Some examples of electrolytes are sodium, potassium, chloride, and calcium. Electrolytes are primarily responsible for the movement of nutrients into cells and the movement of wastes out of cells.
 
Electroporation Therapy
EPT.  Treatment that generates electrical pulses through an electrode placed in a tumor to enhance the ability of anticancer drugs to enter tumor cells.
 
Encapsulated
Confined to a specific, localized area and surrounded by a thin layer of tissue.
 
Enchondroma
A benign (noncancerous) growth of cartilage in bones or in other areas where cartilage is not normally found.
 
Endometrium
The layer of tissue that lines the uterus.
 
Endorphin
A morphine-like chemical that is made naturally in the brain and relieves pain.
 
Endoscope
A thin, tube-like instrument used to look at tissues inside the body. An endoscope has a light and a lens for viewing and may have a tool to remove tissue.
 
Epidemiology
The study of the patterns, causes, and control of disease in groups of people.
 
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.
 
F
 
Familial Cancer
Cancer that occurs in families more often than would be expected by chance. These cancers often occur at an early age, and may indicate the presence of a gene mutation that increases the risk of cancer. They may also be a sign of shared environmental or lifestyle factors.
 
FDA
Food and Drug Administration. An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The FDA also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called Food and Drug Administration.
 
G
 
Genitourinary System
The parts of the body that play a role in reproduction, getting rid of waste products in the form of urine, or both.
 
Genome
The complete genetic material of an organism.
 
Germ Cell
A reproductive cell of the body. Germ cells are egg cells in females and sperm cells in males.
 
Gleason Score
A system of grading prostate cancer tissue based on how it looks under a miscroscope.  Gleason scores range from 2 to 10 and indicate how likely it is that a tumor will spread.  A low Gleason score means the cancer tissue is similar to normal prostate tissue and the tumor is less likely to spread; a high Gleason score means the cancer tissue is very different from normal and the tumor is more likely to spread.
 
Glial Cell
A type of cell that surrounds nerve cells and holds them in place. Glial cells also insulate nerve cells from each other.
 
Gonad
The part of the reproductive system that produces and releases eggs (ovary) or sperm (testicle/testis).
 
Grading
A system for classifying cancer cells in terms of how abnormal they appear when examined under a microscope. The objective of a grading system is to provide information about the probable growth rate of the tumor and its tendency to spread. The systems used to grade tumors vary with each type of cancer. Grading plays a role in treatment decisions.
 
Gynecologic
Having to do with the female reproductive tract (including the cervix, endometrium, fallopian tubes, ovaries, uterus, and vagina).
 
Gynecologic Cancer
Cancer of the female reproductive tract, including the cervix, endometrium, fallopian tubes, ovaries, uterus, and vagina.
 
Gynecologic Oncologist
A doctor who specializes in treating cancers of the female reproductive organs.
 
 
H
 
Hamartoma
A benign (noncancerous) growth made up of an abnormal mixture of cells and tissues normally found in the area of the body where the growth occurs.
 
Hand-Foot Syndrome
A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also called palmar-plantar erythrodysesthesia.
 
Hematologic Cancer
A cancer of the blood or bone marrow, such as leukemia or lymphoma.
 
Hematologist
A doctor who specializes in treating blood disorders.
 
Hemoglobin
The substance inside red blood cells that binds to oxygen and carries it from the lungs to the tissues.
 
Herbal Medicine
A type of medicine that uses roots, stems, leaves, flowers, or seeds of plants to improve health, prevent disease, and treat illness.
 
High-Risk Cancer
Cancer that is likely to recur (come back), or spread.
 
Hormone therapy
Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. The presence of some hormones can cause certain cancers to grow. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy are used to reduce the production of hormones or block them from working.
 
Hospice
A program that provides special care for people who are near the end of life and for their families, either at home, in freestanding facilities, or within hospitals.
 
HPV
Human papillomavirus. A member of a family of viruses that can cause abnormal tissue growth (for example, genital warts) and other changes to cells. Infection with certain types of HPV increases the risk of developing cervical cancer. Also called human papillomavirus.
 
 
I
 
Immune System
The complex group of organs and cells that defends the body against infections and other diseases.
 
Implant 
A substance or object that is put in the body as a prosthesis, or for treatment or diagnosis.
 
Implant Radiation Therapy
A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, radiation brachytherapy, and internal radiation therapy.
 
Infiltrating Cancer
Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called invasive cancer.
 
Invasive Cancer
Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called infiltrating cancer.
 
Irradiation
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 materials placed in the body near cancer cells (internal radiation therapy). Systemic irradiation uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called radiation therapy and radiotherapy.
 
 
J
 
Jewett Staging System 
A staging system for prostate cancer that uses ABCD. “A” and “B” refer to cancer that is confined to the prostate. “C” refers to cancer that has grown out of the prostate but has not spread to lymph nodes or other places in the body. “D” refers to cancer that has spread to lymph nodes or to other places in the body. Also called the ABCD rating or the Whitmore-Jewett staging system.
 
 
K
 
Kahler’s disease
A type of cancer that begins in plasma cells (white blood cells that produce antibodies). Also called multiple myeloma, myelomatosis, or plasma cell myeloma.
 
 
Killer Cell
A white blood cell that attacks tumor cells and body cells that have been invaded by foreign substances.
 
 
L
 
Laboratory Study
Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.
 
Laboratory Test
A medical procedure that involves testing a sample of blood, urine, or other substance from the body. Tests can help determine a diagnosis, plan treatment, check to see if treatment is working, or monitor the disease over time.
 
Lacrimal Gland
A gland that secretes tears. The lacrimal glands are found in the upper, outer part of each eye socket.
 
Late Effects
Side effects of cancer treatment that appear months or years after treatment has ended. Late effects include physical and mental problems and second cancers.
 
Latent
Describes a condition that is present but not active or causing symptoms.
 
LED Therapy
Light-emitting diode therapy. Treatment with drugs that become active and may kill cancer cells when exposed to light. LED therapy is a type of photodynamic therapy, which uses a special type of light to activate the drug. Also called light-emitting diode therapy.
 
LEEP
Loop electrosurgical excision procedure. A technique that uses electric current passed through a thin wire loop to remove abnormal tissue. Also called loop excision and loop electrosurgical excision procedure.
 
Leiomyoma (LY-oh-my-OH-muh)
A benign smooth muscle tumor, usually in the uterus or gastrointestinal tract. Also called fibroid.
 
Leiomysosarcoma (LY-oh-MY-oh-sar-KOH-muH)
A malignant (cancerous) tumor of smooth muscle cells that can arise almost anywhere in the body, but is most common in the uterus, abdomen, or pelvis.
 
 
Leukocyte (LOO-koh-site)
A white blood cell. Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infection and other diseases.
 
Limb Perfusion (per-FYOO-zhun)
A technique that may be used to deliver anticancer drugs directly to an arm or leg. The flow of blood to and from the limb is temporarily stopped with a tourniquet, and anticancer drugs are put directly into the blood of the limb. This allows the person to receive a high dose of drugs in the area where the cancer occurred. Also called isolated limb perfusion.
 
Limbic System (LIM-bik SIS-tem)
A network of structures in the brain involved in memory and emotions.
 
Lipoma (lih-POH-muh)
A benign (not cancer) tumor made of fat cells.
 
Living Will
A type of legal advance directive in which a person describes specific treatment guidelines that are to be followed by health care providers if he or she becomes terminally ill and cannot communicate. A living will usually has instructions about whether to use aggressive medical treatment to keep a person alive (such as CPR, artificial nutrition, use of a respirator).
 
 
 
Lynch Syndrome
An inherited disorder in which affected individuals have a higher-than-normal chance of developing colorectal cancer and certain other types of cancer, usually before the age of 50. Also called hereditary nonpolyposis colon cancer and HNPCC.
 
 
M
 
Magnetic Resonance Imaging - 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 MRI, nuclear magnetic resonance imaging, and NMRI.
 
Maintenance Therapy
Treatment that is given to help a primary (original) treatment keep working. Maintenance therapy is often given to help keep cancer in remission.
 
Mammography (ma-MAH-gruh-fee)
The use of x-rays to create a picture of the breast.
 

 Video  The pros and cons of mammography

 

 Video  When should a women get her first mammogram?

 
Metastasis  (meh-TAS-tuh-sis)
The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).
 
Metastasize  (meh-TAS-tuh-size)
To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.
 
Metastatic  (meh-tuh-STA-tik)
Having to do with metastasis, which is the spread of cancer from one part of the body to another.
 
Metastatic Cancer (meh-tuh-STA-tik KAN-ser)
Cancer that has spread from the place in which it started to other parts of the body.
 
Microwave Therapy
A type of treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs. Also called microwave thermotherapy.
 
 
N
 
Nicotine
A plant alkaloid, found in the tobacco plant, and addictive central nervous system (CNS) stimulant that causes either ganglionic stimulation in low doses or ganglionic blockage in high doses. Nicotine acts as an agonist at the nicotinic cholinergic receptors in the autonomic ganglia, at neuromuscular junctions, and in the adrenal medulla and the brain. Nicotine's CNS-stimulating activities may be mediated through the release of several neurotransmitters, including acetylcholine, beta-endorphin, dopamine, norepinephrine, serotonin, and ACTH. As a result, peripheral vasoconstriction, tachycardia, and elevated blood pressure may be observed with nicotine intake. This agent may also stimulate the chemoreceptor trigger zone, thereby inducing nausea and vomiting.
 
O
 
Occult Primary Tumor
Cancer in which the site of the primary (original) tumor cannot be found. Most metastases from occult primary tumors are found in the head and neck.
 
Olfactory System (ol-FAK-tuh-ree SIS-tem)
The parts of the body involved in sensing smell, including the nose and many parts of the brain. Smell may affect emotion, behavior, memory, and thought.
 
Omega-3 Fatty Acid
A type of fat obtained in the diet and involved in immunity.
 
Oncologist
A doctor who specializes in treating cancer. Some oncologists specialize in a particular type of cancer treatment. For example, a radiation oncologist specializes in treating cancer with radiation.
 
 
 
 
P
 
Pack Year
A way to measure the amount a person has smoked over a long period of time. It is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked. For example, 1 pack year is equal to smoking 1 pack per day for 1 year, or 2 packs per day for half a year, and so on.
 
Palliative Care (PA-lee-uh-tiv...)
Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of palliative care is to prevent or treat as early as possible the symptoms of the disease, side effects caused by treatment of the disease, and psychological, social, and spiritual problems related to the disease or its treatment. Also called comfort care, supportive care, and symptom management.
  
 
Pap Smear
A procedure in which cells are scraped from the cervix for examination under a microscope. It is used to detect cancer and changes that may lead to cancer. A Pap smear can also show noncancerous conditions, such as infection or inflammation. Also called a Pap test.
 
Pathologist  (puh-THAH-loh-jist)
A doctor who identifies diseases by studying cells and tissues under a microscope.
 
Pathology Report
The description of cells and tissues made by a pathologist based on microscopic evidence, and sometimes used to make a diagnosis of a disease.
 
PCA / Patient-Controlled Analgesia
A method of pain relief in which the patient controls the amount of pain medicine that is used. When pain relief is needed, the person can receive a preset dose of pain medicine by pressing a button on a computerized pump that is connected to a small tube in the body.
 
PET Scan
Positron emission tomography 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.
 
Polyp (PAH-lip)
A growth that protrudes from a mucous membrane.
 
Precancerous Polyps (pree-KAN-seh-rus PAH-lips)
Growths that protrude from a mucous membrane. Precancerous polyps may (or are likely to) become cancer.
 
Preleukemia
A group of diseases in which the bone marrow does not make enough healthy blood cells. Also called myelodysplastic syndromes and smoldering leukemia. 
 
Premalignant  (pree-muh-LIG-nunt)
A term used to describe a condition that may (or is likely to) become cancer. Also called precancerous.
 
Prognosis (prog-NO-sis)
The likely outcome or course of a disease; the chance of recovery or recurrence.
 
 
PTSD
Post-traumatic stress disorder. An anxiety disorder that develops in reaction to physical injury or severe mental or emotional distress, such as military combat, violent assault, natural disaster, or other life-threatening events. Having cancer may also lead to PTSD. Symptoms interfere with day-to-day living and include reliving the event in nightmares or flashbacks; avoiding people, places, and things connected to the event; feeling alone and losing interest in daily activities; and having trouble concentrating and sleeping. Also called post-traumatic stress disorder.
 
 
Q
 
Quality Of Life   The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.
 
 
R
 
Radiation Brachytherapy
A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, internal radiation therapy, and implant radiation therapy.
 
Radiation Fibrosis
The formation of scar tissue as a result of radiation therapy.
 
Radiation Necrosis
The death of healthy tissue caused by radiation therapy. Radiation necrosis is a side effect of radiation therapy given to kill cancer cells, and can occur after cancer treatment has ended.
 
Radiation Oncologist
A doctor who specializes in using radiation to treat cancer.
 
Radiation therapy
A cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
 
Radioactive Seed
A small, radioactive pellet that is placed in or near a tumor. Cancer cells are killed by the energy given off as the radioactive material decays (breaks down).
 
Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
 
Radiosurgery
A type of external radiation therapy that uses special equipment to position the patient and precisely give a single large dose of radiation to a tumor. It is used to treat brain tumors and other brain disorders that cannot be treated by regular surgery. It also is being studied in the treatment of other types of cancer. Also called stereotaxic radiosurgery, stereotactic radiosurgery, and radiation surgery.
 
Recurrence
Cancer that has returned after a period of time during which the cancer could not be detected. The cancer may come back to the same place as the original (primary) tumor or to another place in the body. Also called recurrent cancer.
 
Recurrent Cancer
Cancer that has returned after a period of time during which the cancer could not be detected. The cancer may come back to the same place as the original (primary) tumor or to another place in the body. Also called recurrence.
 
Refractory Cancer
Cancer that does not respond to treatment. The cancer may be resistant at the beginning of treatment or it may become resistant during treatment. Also called resistant cancer.
 
Relapse
The return of signs and symptoms of cancer after a period of improvement.
 
Relative Survival Rate
A specific measurement of survival. For cancer, the rate is calculated by adjusting the survival rate to remove all causes of death except cancer. The rate is determined at specific time intervals, such as 2 years and 5 years after diagnosis.
 
Remission
A decrease in or disappearance of signs and symptoms of cancer. In partial remission, some, but not all, signs and symptoms of cancer have disappeared. In complete remission, all signs and symptoms of cancer have disappeared, although cancer still may be in the body.
 
Response Rate
The percentage of patients whose cancer shrinks or disappears after treatment.
 
Risk Factor
Something that may increase the chance of developing a disease. Some examples of risk factors for cancer include age, a family history of certain cancers, use of tobacco products, certain eating habits, obesity, lack of exercise, exposure to radiation or other cancer-causing agents, and certain genetic changes.
 
 
S
 
Salvage Therapy   
Treatment that is given after the cancer has not responded to other treatments.
 
Schedule
In clinical trials, the step-by-step plan for how patients are to be treated; for example, the drug or type of radiation therapy that is to be given, the method by which it is to be given, the amount of time between courses, and the total length of treatment.
 
Secondary Cancer  
A term that is used to describe either a new primary cancer or cancer that has spread from the place in which it started to other parts of the body.
 
Secondhand Smoke
Smoke that comes from the burning of a tobacco product and smoke that is exhaled by smokers. Inhaling secondhand smoke is called involuntary or passive smoking. Also called environmental tobacco smoke and ETS.
 
Sentinel Lymph Node  
The first lymph node to which cancer is likely to spread from the primary tumor. When cancer spreads, the cancer cells may appear first in the sentinel node before spreading to other lymph nodes.
 
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.
 
Sentinel Lymph Node Mapping
The use of dyes and radioactive substances to identify the first lymph node to which cancer is likely to spread from the primary tumor. Cancer cells may appear first in the sentinel node before spreading to other lymph nodes and other places in the body.
 
Serum Tumor Marker Test
A blood test that measures the amount of substances called tumor markers (or biomarkers). Tumor markers are released into the blood by tumor cells or by other cells in response to tumor cells. A high level of a tumor marker may be a sign of cancer.
 
Shunt
In medicine, a passage that is made to allow blood or other fluid to move from one part of the body to another. For example, a surgeon may implant a tube to drain cerebrospinal fluid from the brain to the abdomen. A surgeon may also change normal blood flow by making a passage that leads from one blood vessel to another.
 
Sigmoidoscope (sig-MOY-doh-skope)
A thin, tube-like instrument used to examine the inside of the colon. A sigmoidoscope has a light and a lens for viewing and may have a tool to remove tissue.
 
Sigmoidoscopy  (sig-MOY-DOS-koh-pee)
Examination of the lower colon using a sigmoidoscope, inserted into the rectum. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called proctosigmoidoscopy.