NCI Dictionary of Cancer Terms
Contains more than 3,500 terms related to cancer and medicine.
-- from National Cancer Institute

Click on a letter or scroll down to find the term you are looking for.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

Absolute neutrophil count (ANC)
Total count of the neutrophils in the blood, which provides an indication of a person's ability to fight infection. To calculate the ANC, add the percentages of seg neutrophils and band neutrophils, divide by 100, and multiply by the total white blood count. (more on ANC)

Acute
Having or experiencing a rapid onset and short but severe course.

ALL (acute lymphoblastic leukemia)
An acute form of leukemia occurring predominantly in children, characterized by the unrestrained production of immature lymphoblasts (a type of white cell) in the blood-forming tissues, particularly the bone marrow, spleen, and lymph nodes. For more detailed information, see Health Professional Version from NCI.

Allogeneic transplant
Type of bone marrow transplant in which the marrow is donated by another person.

Alopecia
Hair loss; a common side effect of chemotherapy.

ANC (Absolute neutrophil count)
Total count of the neutrophils in the blood, which provides an indication of a person's ability to fight infection. To calculate the ANC, add the percentages of seg neutrophils and band neutrophils, divide by 100, and multiply by the total white blood count. (more on ANC)

Anemia
Condition in which there is a reduction in the number of circulating red blood cells.

Anesthesia
Partial or total loss of sensation, with or without loss of consciousness, induced by the administration of a drug.

Anesthesiologist
A doctor who specializes in the study and administration of anesthesia.

ARA-C
Cytarabine kills cancer cells by disrupting DNA. Given by IV, intrathecal or subcutaneous injection.

Asparaginase
An anticancer drug that is an enzyme. (see PEG)

Attending physician
Doctor on the staff of a hospital who has completed medical school, residency, and fellowship.

Asymptomatic
Without symptoms.

Autologous
From the same person. An autologous bone marrow transplant is a procedure in which bone marrow that has been removed from a patient is given back to that patient.

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B

B-cells
Type of lymphocyte (white cell) that helps produce antibodies that destroy foreign substances.

Bactrim
A prophylactic antibiotic that children and teens on chemotherapy take antibiotics two to three days each week to prevent pneumocytis pneumonia (PCP). The anitbiotic of choice for PCP prevention is a combination drug containing sulfamethoxazole and trimethoprim. Given as pill or liquid by mouth.

Basophil
Type of granulocyte (white cell) that plays a special role in allergic reactions and helps in the healing of inflammations.

Blast cell
An undifferentiated normal cell in an early stage of development; also means a leukemic cell of indeterminable type.

Blood-brain barrier
A network of blood vessels located around the central nervous system with very closely spaced cells that make it difficult for potentially toxic substances-including anticancer drugs-to enter the brain and spinal cord.

Blood transfusion
The administration of blood or blood products into a blood vessel.

Blood type
Identification of the proteins in a person's blood cells so that transfusions can be given with compatible blood products. Examples of blood types are A+, A-, B+, B-, AB+, AB-, O+, O-.

Bone marrow
Soft, inner part of large bones that makes blood cells.

Bone marrow aspiration (BMA)
Process in which a sample of fluid and cells is withdrawn from the bone marrow using a hollow needle.

Bone marrow biopsy
The removal of a sample of solid tissue from the bone marrow.

Bone marrow transplant (BMT)
A procedure in which doctors replace bone marrow that has been destroyed by high doses of chemotherapy and/or radiation.

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.

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C

CAT scan
A computerized axial tomography scan is more commonly known by its abbreviated name, CAT scan or CT scan. It is an x-ray procedure which combines many x-ray images with the aid of a computer to generate cross-sectional views and, if needed, three-dimensional images of the internal organs and structures of the body.

CBC (complete blood count)
The CBC is the most common blood test. It analyzes the three major types of cells in blood: red blood cells, white blood cells, and platelets, in a cubic millimeter of blood. The CBC counts these cells, measures hemoglobin (the oxygen-carrying molecule in red blood cells), estimates the red cells' volume, and sorts the white blood cells into five subtypes.

CNS (central nervous system)
The brain, spinal cord, and nerves.

Cancer
A term for diseases in which abnormal cells divide without control.

Cerebrospinal fluid (CSF)
Fluid that surrounds and bathes the brain and spinal cord and provides a cushion from shocks.

Children's Cancer Group (CCG)
An organization that designs and monitors pediatric clinical trials.

Chemotherapy
Treatment of disease with drugs. The term usually refers to cytotoxic drugs given to treat cancer.

Chromosome
A structure in the nucleus of a cell that contains genetic material. Normally, 46 chromosomes are inside each human cell.

Clinical trial
A carefully designed and executed investigation of a drug, drug dosage, combination of drugs, or other method of treating disease. Each trial is designed to answer one or more scientific questions and to find better ways to prevent or treat disease.

Complete Blood Count (CBC)
The complete blood count is the most common blood test. It analyzes the three major types of cells in blood: red blood cells, white blood cells, and platelets, in a cubic millimeter of blood. The CBC counts these cells, measures hemoglobin (the oxygen-carrying molecule in red blood cells), estimates the red cells' volume, and sorts the white blood cells into five subtypes.

Consolidation
Portion of the protocol which consists of new combinations of drugs to destroy any cancer cells that survived induction.

Cord blood
Blood taken post partum from the umbilical cord

Cure
Cure is defined as 5 years or more of remission (cancer-free survival).

Cytarabine
Kills cancer cells by disrupting DNA. Given by IV, intrathecal or subcutaneous injection. Also called ARA-C.

Cytomegalovirus (CMV)
One of a group of herpes viruses that can cause fatal infections in immunosuppressed patients.

Cytotoxic
Causing the death of cells.

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D

Delayed intensification (DI)
Portion of treatment that comes after the initial induction, consolidation, and interim maintenance. The purpose of this phase is to destroy any remaining cancer cells.

Differentiation
The process by which cells mature and become specialized.

Dilaudid
A narcotic pain reliever. Also called Hydromorphone. Given by IV injection or pill by mouth.

Doxorubicin (DOXO)
An anticancer drug that belongs to the family of drugs called antitumor antibiotics. It is an anthracycline given by IV injection or infusion.

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E

Echocardiogram
A diagnostic test that uses ultrasound to visualize the interior of the heart and determine how effectively it is functioning.

Electrocardiogram (ECG, EKG)
A graphic record of the electric current produced by the contraction of the heart.

EMLA cream
An emulsion which contains two anesthetics, lidocaine and prilocaine. A local anesthetic to prevent pain. The cream is applied to the skin and covered with an airtight dressing one to two hours before procedures such as spinal tap, bone marrow aspiration, port access or injection.

Enterovirus meningitis
Enterovirus meningitis is a type of viral meningitis that usually occurs in the summer and fall, with acute onset of symptoms that last one to two weeks. If Enterovirus is a possibility, a sample of cerebrospinal fluid should be sent for this viral culture. (see meningitis)

Eosinophil
A type of white cell that responds to allergic reactions as well as foreign bacteria.

Erythrocytes
Red blood cells.

Event-free survival (EFS)
Survival with out relapse or death.

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F

Fellow
A physician who has completed four years of medical school and several years of residency, and is pursuing additional training in a specialized field.

Finger poke
When a laboratory technician pricks the fingertip to obtain a small sample of blood.

G

Graft
Tissue taken from one person (donor) and transferred to another person (recipient or host).

Graft-versus-host disease
A condition that may develop after allogenic bone marrow transplantation in which the transplanted marrow (graft) attacks the patient's (host's) organs.

Granulocytes
A type of white cell that destroys foreign substances in the body such as viruses, bacteria, and fungi.

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H

Hematocrit
The measurement of the proportion of cells to plasma in a sample of blood. Sometimes called packed cell volume (PCV).

Hematologist
Physician who specializes in the diagnosis and treatment of disorders of blood and blood-forming tissues.

Hemoglobin (Hgb)
The protein found in red blood cells that carries oxygen. Normal range for Hgb is 11 - 18 g/dL

Heparin solution
An anticoagulant injected into indwelling catheters between uses to prevent clots.

Host
In bone marrow transplantation, the person who receives the marrow.

Human leukocyte antigens (HLAs)
Proteins on the surface of cells that are important in transplantation and transfusion. For BMTs, the HLAs on white cells of the patient and potential donor are compared. A perfect HLA match occurs only between identical twins.

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I

Infusion pump
A small, computerized device which allows drugs to be given at home through an IV or indwelling catheter.

Immune system
Complex system by which the body is able to protect itself from foreign invaders.

Immunosuppression
When the immune system is suppressed, leaving the body susceptible to infection.

Induction
The first part of the chemotherapy protocol for treating some types of leukemia in which several powerful chemotherapy drugs are given to kill as many cancer cells as possible.

Institutional Review Board (IRB)
Group made up of scientists, clergy, doctors, and citizens from the community, which approves and reviews all research taking place at an institution.

Intern
Recent medical school graduate who is receiving his/her first year of supervised practical training in medical and surgical care of patients in hospitals.

Intrathecal
Injecting drugs into the cerebrospinal fluid during a spinal tap.

Intravenous-access line (IV)
A hollow metal or plastic tube which is inserted into a vein and attached to tubing, allowing various solutions or medicines to be directly infused into the blood.

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L

Leukemia
Disease characterized by the unrestrained growth of abnormal white cells in the bone marrow, and often in the spleen and liver; these cancerous cells usually appear in the peripheral blood and may also invade other organs.

Leukocytes
White blood cells.

Leukopenia
A below-normal number of white cells.

Lidocaine
Drug most commonly used for local anesthesia.

Lumbar puncture (LP; spinal tap)
Procedure in which a needle is inserted between the vertebrae of the back to obtain a sample of cerebrospinal fluid and/or inject medication.

Lymph
A clear, colorless fluid found in lymph vessels throughout the body, which carries cells to fight infection.

Lymph nodes
Rounded bodies of lymphatic tissues found in lymph vessels.

Lymph system
A system of vessels and nodes throughout the body which helps filter out bacteria as well as performs numerous other functions.

Lymphoblast
An immature lymphocyte.

Lymphocytes
Any of a group of white blood cells, of crucial importance to the immune system, which defends the body against dangerous invading organisms.The principle types are B-lymphocytes and T-lymphocytes (also referred to as B-cells and T-cells respectively). Lymphocytes produce antibodies, which are specific proteins that attack and help destroy specific germs, but most of these circulating in the blood either attack invaders (these are called cytotoic lymphocytes) or coordinate the attack of antibodies (these coordinators are called helper lymphocytes). They are especially important in fighting viral infections, like colds and flu.

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M

Maintenance
Part of a leukemia protocol for treating ALL. It follows the intensive induction and consolidation phases and helps destroy any remaining cancer cells.

Medical student
Student who has completed four years of college and is enrolled in medical school.

Meningitis
Meningitis is an infection of the fluid of a person's spinal cord and the fluid that surrounds the brain. People sometimes refer to it as spinal meningitis. Meningitis is usually caused by a viral or bacterial infection. Knowing whether meningitis is caused by a virus or bacterium is important because the severity of illness and the treatment differ. Viral meningitis is generally less severe and resolves without specific treatment, while bacterial meningitis can be quite severe and may result in brain damage, hearing loss, or learning disability. Symptoms: High fever, headache, and stiff neck are common symptoms of meningitis in anyone over the age of 2 years. These symptoms can develop over several hours, or they may take 1 to 2 days. Other symptoms may include nausea, vomiting, discomfort looking into bright lights, confusion, and sleepiness. Diagnosis: Early diagnosis and treatment are very important. The diagnosis is usually made by bacterial or viral culture from a sample of spinal fluid. The spinal fluid is obtained by performing a spinal tap, in which a needle is inserted into an area in the lower back where fluid in the spinal canal is readily accessible.

Mercaptopurine
An antimetabolite that replaces part of the backbone of DNA. Also called 6-MP, Purinethol. Pills given by mouth.

Methotrexate (MTX)
An antimetabolite which replaces folic acid in cells, preventing them from dividing. Children should not be given extra folic acid in vitamins or the MTX will not be effective. Given by IV, intrathecal injection or pills by mouth.

Monocytes
Type of white blood cell.

Morphine
A narcotic pain reliever derived from the opium plant. Given by IV injection, liquid by mouth or pill by mouth.

MRI
A MRI is also called magnetic resonance imaging. It is an imaging method used by radiologists to view internal body structures using combinations of radio waves and magnetic fields. An MRI is a large noninvasive device which utilizes the properties of magnetism to create nondestructive, three-dimensional, internal images of the soft tissues of the body, including the brain, spinal cord and muscle.

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N

Neurotoxic
Substance which is poisonous to the brain, spinal cord, and/or nerve cells.

Neutropenia
Condition when the body does not have enough neutrophils (a type of infection-fighting white cell).

Neutrophils
The most numerous of the granulocytic white cells, which migrate through the bloodstream to the site of infection, where they ingest and destroy bacteria. Neutrophils play a key role in the body's defense against invading bacteria. They surround, engulf, and destroy invading microbes. If there are not enough neutrophils in the bloodstream, a person is at risk for developing serious infections.

Nutritionist
A professional who analyzes nutritional requirements and gives advice on how to eat an appropriate diet for any condition.

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O

Oncologist
Doctor who specializes in the treatment of cancer.

Oncology
Study of cancer.

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P

Pathologist
Doctor who specializes in examining tissue and diagnosing disease.

Pediatrician
Doctor who specializes in the care and development of children and the treatment of their diseases.

Pediatric Oncology Group (POG)
An organization which designs and monitors pediatric clinical trials.

PEG-Asparaginase (PEG)
Enzymes that block protein production in cancer cells to prevent them from reproducing. Intramuscular injection.

Petechiae
Small, reddish spots under the skin caused by hemorrhage.

Plasma
The liquid part of the lymph and the blood.

Platelet (Plt)
These disc-shaped blood cells play an important role in blood clotting and the prevention of bleeding. There are about 100,000 to 300,000 platelets in each cubic millimeter of blood. When a blood vessel is damaged or cut, platelets clump together and plug up the hole until the blood clots. If the platelet count is too low, a person can be in danger of bleeding in any part of the body. Normal range for Plt is 150 - 450 x 10^3/uL

Port-a-cath
Indwelling catheter which has a small portal under the skin of the chest attached to tubing which goes into the heart.

Preimplantation Genetic Diagnosis (PGD)
Preimplantation Genetic Diagnosis (PGD) is a powerful technique allowing the identification of disease-free embryos that are human leukocyte antigen (HLA) matched with the sibling in the family with a life-threatening disease. The purpose of PGD in bone marrow transplantation is to guarantee the birth of a child with HLA matched stem cells that can be used to treat the affected sibling. Read how one family conceived a baby by in vitro fertilization and PGD, providing a stem cell donor for another child.

Prognosis
Expected or probable outcome.

Prophylactic antibiotics
Children and teens on chemotherapy take antibiotics two to three days each week to prevent pneumocytis pneumonia (PCP). The anitbiotic of choice for PCP prevention is a combination drug containing sulfamethoxazole and trimethoprim. Brand names: Bactrim and Septra. Given as pill or liquid by mouth.

Prophylaxis
An attempt to prevent disease.

Protocol
The "recipe" for a child's cancer treatment. Outlines the drugs that will be taken, when they will be taken, and in what dosages. Also includes the dates for procedures (e.g., bone marrow aspiration schedule).

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R

Rad
Radiation absorbed dose. A unit of measurement of the absorbed dose of radiation.

Radiation
High-energy rays which are used to kill or damage cancer cells.

Radiologist
Doctor who specializes in using radiation and radioactive isotopes to diagnose and treat disease.

Randomized
Chosen at random. In a randomized research project, a computer chooses which patients receive the experimental treatment(s) and which patients receive the standard treatment.

Relapse
A return of the cancer after its apparently complete disappearance.

Remission
Disappearance of detectable disease.

Resident
Physician who has completed four years of medical school and one year of internship, and who is continuing his or her clinical training.

Right atrial catheter
Indwelling catheter with tubing that extends into the heart which provides access for drawing blood and injecting medication.

Risk Groups
Children with ALL are usually treated according to risk groups defined by both clinical and laboratory features. Standard risk - Includes children 1 to 9 years of age who have a white blood cell count of less than 50,000/µL at diagnosis. High risk - Includes children younger than 1 year of age or older than 9 years of age and children who have a white blood cell count of 50,000/µL or more at diagnosis.

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S

Side effect
Unintentional or undesirable secondary effect of treatment.

Spinal tap
Procedure in which a needle is inserted between the vertebrae of the back to obtain a sample of cerebrospinal fluid and/or inject medication. Also called a lumbar puncture (LP).

Staphylococcus epidermidis
Bacteria normally present on the skin which can infect the blood through an indwelling catheter.

Stem cells
Cells from which all blood cells develop.

Streptokinase
Enzyme sometimes used to dissolve blood clots in catheter tubing.

Stroke
Loss of consciousness and paralysis caused by bleeding into the brain or clotting that blocks blood flow to a portion of the brain, causing injury or death to brain tissue.

Subcutaneous port
Type of indwelling catheter comprised of a portal under the skin of the chest attached to tubing leading into the heart.

Systemic
Affecting the body as a whole.

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T

T-cell
Type of lymphocyte (white cell), derived from the thymus, that attacks infected cells, foreign tissue, and cancer cells.

Thrombocytes
Platelets.

Thymus
Small gland located behind the breast bone and between the lungs that plays a major role in the immune system.

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U

Urokinase
Enzyme sometimes used to dissolve clots in catheter tubing.

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V

Vancomycin
Antibiotic commonly used to treat infections in indwelling catheters.

Vincristine (VCR)
Vincristine is an alkyloid derived from the periwinkle plant. It causes cells to stop dividing. Side effects are most pronounced during induction and consolidation when given weekly. It is generally better tolerated during maintenance when it is given monthly. Given by IV injection.

Vital signs
Term that describes a patient's pulse, rate of breathing, and blood pressure.

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W

White blood cells (WBC)
Any of a group of blood cells that have no hemoglobin and migrate into tissues to fight infection and digest cell debris. WBC circulate in the blood and lymphatic system and harbor in the lymph glands and spleen. They are part of the immune system responsible for both directly (T cells and macrophages) and indirectly (B cells producing antibodies) attacking foreign invaders of the body. Normal range for WBC is 4.5 - 10.5 x 10^3/uL

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