Medical Dictionary
If you are reading this, you have probably learned that you or someone you know has cancer. Oncology - or the study of cancer - has its own complex vocabulary, as you have probably figured out.
The TLC Medical Dictionary explains the most common terms you need to know to completely understand your treatment and what is happening to your body. If you hear a word or expression not listed here, don't be afraid to ask someone on your medical team. Or you can email the editor and a medical advisor will get back to you with an explanation.
abdomen
(ab-do-men) The part of your body between the chest and the pelvis containing the stomach (with the lower part of the esophagus), small and large intestines, liver, gallbladder, spleen, pancreas, and bladder
ablative therapy
(ab-lay-tive ) Treatment that removes or destroys the function of an organ or system. For example, high dose chemotherapy and radiation before a bone marrow transplant is considered ablative therapy because it wipes out your immune system.
absolute neutrophil count
(ANC) The percentage of polys and bands that are part of your total white blood count. If your ANC. is less than 1,000, you are very prone to infection.
adjuvant therapy
- (add-joo-vunt) Treatment used in addition to your main treatment. It usually refers to chemotherapy, radiation therapy, or immunotherapy added after surgery to increase the chances of curing your disease or keeping it in check.
afebrile
Having no fever, normal temperature
alkaline
Any substance that can neutralize acids. Alkaline urine is needed to neutralize uric acid, the product of tumor cell breakdown that can be harmful to your kidneys.
alopecia
(al-o-pee-shuh) Hair loss. This often occurs as a result of chemotherapy or from radiation therapy to the head. In most cases, the hair grows back after treatment ends.
alternative therapy
Non-conventional treatment that may not be medically proven. Some alternative therapies may have dangerous or even life-threatening side effects. With others, the main danger is that you may lose the opportunity to benefit from conventional therapy. It is recommended that you discuss the use of alternative therapies with your health care team. See also complementary therapy.
ambulator
The ability to walk; not confined to bed.
amputation
The surgical removal of a diseased body part.
analgesic
A drug used for reducing pain.
anaphylaxis
An allergic reaction ranging from relatively mild (hives) to very serious (shock).
anemia
- (uh-neem-ee-uh) Low red blood cell count which can cause you to feel fatigued and have shortness of breath. Anemia can be caused by a variety of conditions and diseases.
anesthesiologist
- (an-es-thee-zee-ol-o-jist) A doctor who specializes in giving medicines or other agents that prevent or relieve pain, especially during surgery.
anorexia
The lack of desire for food; no appetite.
anterior
Located in the front, opposite the posterior
antibiotic
Drug used to kill organisms that cause disease. Since some cancer treatments can reduce your body’s ability to fight infection, antibiotics may be used to treat or prevent (prophylactic) these infections.
antibody
A protein produced by immune system cells and released into the blood. Antibodies defend against foreign agents, such as bacteria. These agents contain certain substances called antigens. Each antibody works against a specific antigen.
anticoagulant
Drug that reduces the blood’s ability to clot.
antiemetic
(an-ti-eh-MEH-tik) (anti-nausea) A drug that prevents or relieves nausea and vomiting, common side effects of chemotherapy.
antifungal
A medicine that kills fungi, organisms that cause infections. Kids undergoing treatment for cancer are especially vulnerable to fungal infections.
antigent
(an-tuh-jen) A substance that causes your body’s immune system to react. This reaction often involves production of antibodies. For example, your immune system’s response to antigens that are part of bacteria and viruses helps you resist infections. Cancer cells have certain antigens that can be found by laboratory tests. They are important in cancer diagnosis and in watching response to treatment.
antihistamine
A medicine used to relieve the symptoms of allergies like hives, stuffy nose, etc.
Bacteria
A term for a group of living organisms, larger than viruses that may be seen only through a microscope. In general, most are harmless unless body resistance is lowered.
band
Young, white blood cells; important in defending your body against infection.
benign
Not malignant or cancerous.
beta-carotene
An early form of vitamin A that is found mainly in yellow and orange vegetables and fruits. It functions as an antioxidant and may play a role in cancer prevention.
bilateral
Two sides of your body.
bile
A yellow-green fluid made by your liver from discarded red blood cells and excreted into the intestine where it helps to digest fat.
biopsy
(buy-OP-see) The removal of a sample of tissue to see whether cancer cells are present and to determine an exact diagnosis. There are several kinds of biopsies.
blast cells
Refers to the earliest-formed marrow cells. In acute leukemias, blast cells are similar in appearance to normal blast cells but accumulate in large numbers.
blood
The body fluid that flows through all the vessels except the lymph vessels and performs a number of critical functions. Blood is composed of a liquid portion called plasma and three other components: red blood cells, white blood cells and platelets.
blood chemistries
Multiple chemical determinations of the blood content. These tests are helpful in assessing your kidney and liver function.
blood count
A lab study to evaluate the amount of white blood cells, red blood cells, and platelets.
blood transfusion
The infusion of red blood cells or platelets into your blood stream to replace blood loss or to correct anemia.
blood typing and cross matching
Making sure that the blood from a donor is compatible with yours before a blood transfusion. Blood cells contain factors that are not the same in all people. Before a transfusion can be given, blood samples from the donor and you are typed, or classified according to which of these factors are present. The four principal red blood cell types or groups are A, B, AB or O. Other factors such as Rh factor must also be checked. (see the section on blood transfusions in “What Treatment Really Means”)
bone marrow
The spongy material that fills the cavities of the bones and is the substance in which blood is produced. In order to determine the condition of the marrow, a doctor may take a small sample from one of the bones in the chest, hip, spine or leg. (See the section on bone marrow biopsies)
bone marrow aspiration and biopsy
A procedure in which a needle is placed into the cavity of a bone, usually the hip or breast bone, to remove a small amount of bone marrow for examination under a microscope.
bone marrow transplant (BMT)
A very rigorous treatment for cancer which severely injures or destroys the patient’s bone marrow. You are given high doses of chemotherapy to kill the cancer cells. The drugs also destroy the remaining bone marrow, thus robbing your body of its natural ability to fight infection. Total Body Radiation (TBI) is sometimes administered. § In allogeneic transplantation, bone marrow from another individual, usually a brother or sister with the same tissue type is given to the patient. This bone marrow develops in the patient and eventually begins producing blood cells. § In autologous bone marrow transplantation, some of your own bone marrow is removed and set aside before treatment and then re-infused. It starts producing blood cells a few weeks later. § In umbilical cord blood transplantation, the use of stem cells in blood removed from the umbilical cords of newborns (a very rich source) is used for transplantation.
bone scan
An imaging method that gives important information about the bones, including the location of cancer that may have spread to the bones. A low-dose radioactive substance is injected into a vein and pictures are taken to see where the radioactivity collects, pointing to an abnormality
bowel
Pertaining to your intestines.
brain scan
An imaging method used to find anything not normal in the brain, including brain cancer and cancer that has spread to the brain from other places in the body. A radioactive substance is injected into a vein and pictures are taken to show where the radioactivity collects, indicating an abnormality.
Broviac® catheter
Soft plastic catheters that are surgically placed in one of the neck veins and advanced to the opening of the heart in order to easily administer intravenous solutions and to obtain blood for testing.
“HICKMAN and/or BROVIAC are registered trademarks of C.R. Bard, Inc. and its related company, BCR, Inc.”
cancer
Develops when cells in your body begin to grow out of control. Normal cells grow, divide, and die naturally. Instead of dying, cancer cells continue to grow and form new abnormal cells. Cancer cells often travel to other body parts where they grow and replace normal tissue. This process is called metastasis. Cancer cells develop because of damage to DNA. DNA is in every cell and directs all its activities. When DNA becomes damaged, the body is usually able to repair it. In cancer cells, the damage is not repaired. People can inherit damaged DNA, which accounts for inherited cancers. Many times, DNA becomes damaged by exposure to something in the environment, like smoking. Many cancers have no known cause.
capillaries
Tiny blood vessels located throughout the tissues of your body which connect your arteries with your veins and through which substances pass to nourish your cells.
cardiac
Pertaining to your heart.
catheter
- (CATH-eh-tur) A thin, flexible tube through which fluids enter or leave the body; e.g., a tube to drain urine.
cell
The basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.
cell morphology
Refers to cell types or structure.
cellulitis
Usually means a diffuse infection of the skin and underlying tissue.
central nervous system (CNS)
Refers to the brain and spinal cord.
central venous line
A method of giving IV fluids, blood products and medicines by surgically inserting a catheter into a neck vein that passes into your other large blood vessels. There are many different types of central line catheters that may have multiple ports or lumens. Multiple ports allow more than one IV solution to be given simultaneously. Blood can also be withdrawn from this type of catheter.
charts
Your written medical records.
chemotherapy
Using chemical agents or drugs to destroy malignant cells. Chemotherapy is often used with surgery or radiation to treat cancer. Some chemotherapy treatment plans have different phases: Induction -intensive treatment used to produce a complete remission. Maintenance – drugs given after the initial “induction” to maintain the remission
chronic
A disease process that develops over a long period of time and progresses slowly.
clinical
In general, pertaining to observation and treatment of patients.
clinical trials
Human research studies that test new drugs or treatments and compare them to current, standard treatments. Before a new treatment is used on people, it is studied in the lab. If lab studies suggest the treatment works, it is tested with patients. These human studies are called clinical trials. Questions the researchers want to answer are: Does this treatment work? Does it work better than the one we use now? What side effects does it cause? Do the benefits outweigh the risks? Your doctor may suggest a clinical trial. Participation is voluntary.
cobalt – cobalt treatment
Radiotherapy using gamma rays generated from the breakdown of radioactive cobalt 60.
colon
The large intestine.