Ablative therapy: Treatment that removes or destroys the function of an organ,
for example, removing the ovaries or testicles or having some types of
chemotherapy that cause them to stop working.
Adenocarcinoma: A type of cancer that starts in the glandular tissue, such as in
the ducts or lobules of the breast.
Adenoma: Benign growth starting in the glandular tissue.
Adenomatous polyps: Benign growths of glandular cells, for example, those that
line the inside of the colon or rectum. There are three types of colorectal
adenomas: tubular, villous, and tuberovillous
Adenomatous polyps or adenoma: Benign growth of
glandular cells, for example, those that line the inside of the colon or rectum.
There are three types of colorectal adenomas: tubular, villous, and
tuberovillous. Adenine (A): A nitrogenous base, one member of the base pair AT
Adjuvant therapy : Treatment used in addition to
the main treatment. It usually refers to hormonal therapy, chemotherapy,
radiation therapy, or immunotherapy added after surgery to increase the chances
of curing the disease or keeping it in check.
Adrenal gland : One adrenal gland is located near each kidney. Their main
function is to produce hormones which control metabolism, fluid balance, and
blood pressure. In addition, they produce small amounts of "male"
hormones (androgens) and "female" hormones (estrogens and
Advance directives : Legally binding documents that tell doctors and family what
a person wants for future medical care, including whether to start or when to
stop life-sustaining treatment.
Allele: Alternative form of a genetic locus; a single allele for each locus is
inherited separately from each parent (e.g., at a locus for eye color the allele
might result in blue or brown eyes).
Alopecia: 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 : Use of unproven therapy instead of standard (proven)
therapy. Some alternative therapies have dangerous or even life-threatening side
effects. With others, the main danger is that the patient may lose the
opportunity to benefit from standard therapy. patients considering alternative
or "complementary" therapy should discuss it with their health care
team. (See: complementary therapy).
Alveoli: Air cells of the lungs.
Amino acid: Any of a class of 20 molecules that
are combined to form proteins in living things. The sequence of amino acids in a
protein and hence protein function are determined by the genetic code.
Amplification: An increase in the number of copies of a specific DNA fragment;
can be in vivo or in vitro. See cloning, polymerase chain reaction
Androgen: Any male sex hormone. (Testosterone is
the major androgen.)
Androgen blockade: Use of drugs to disrupt actions of male hormones.
Anemia: Low red blood cell count.
Anesthesia: Loss of feeling or sensation as a result of drugs or gases. General
anesthesia causes loss of consciousness ("puts you to sleep"). Local
or regional anesthesia numbs only a certain area.
Anesthesiologist: Doctor specializing in giving medicines or other agents that
prevent or relieve pain, especially during surgery.
Aneuploid: (See ploidy.)
Angiogenesis: Formation of new blood vessels. Some cancer treatments work by
blocking angiogenesis, preventing blood from reaching the tumor.
Antibiotics: Drugs used to kill organisms that cause disease. Because some
cancer treatments reduce the body's ability to fight infection, antibiotics may
be used to treat or prevent infection.
Antibody: Antibodies defend against foreign agents, such as bacteria. Antibodies
are proteins produced by immune system cells, which then release them into the
blood. (See: antigen).
Antiemetic: Drug that prevents/relieves nausea and vomiting - often common side
effects of chemotherapy.
Antiestrogen: Substance (drug) that blocks the effects of estrogen on tumors.
Antiestrogens are commonly used to treat breast cancer, which depends on
estrogen for growth.
Antigen: Substance that causes the immune system to react - often involving
production of antibodies. For example, antigens that are part of bacteria and
viruses cause the immune system to respond and helps protect people from
infection. Cancer cells also have certain antigens that can be found by lab
tests. These antigens are important in cancer diagnosis and in gauging response
to treatment. Other cancer antigens may even trigger the body's own
Antimetabolites: Substances that interfere with the body's chemical processes,
such as those creating proteins, DNA, and other chemicals needed for healthy
cell growth and cell reproduction. In treating cancer, antimetabolite drugs
disrupt DNA production, which, in turn, prevents cell division and growth of
tumors. (See: DNA.)
Antioxidants: Compounds that stop or retard chemical reactions with oxygen
(oxidation) and are thought to reduce the risk of some cancers. Vitamins C and E
and beta-carotene are some common antioxidants.
Antisense - Antisense drugs work at the genetic
level to interrupt the process by which disease-causing proteins are produced.
Proteins play a central role in virtually every aspect of human metabolism.
Almost all human diseases are the result of inappropriate protein production (or
disordered protein performance). This is true of both host diseases (such as
cancer) and infectious diseases (such as AIDS). Traditional drugs are designed
to interact with protein molecules throughout the body that support or cause
diseases. Antisense drugs are designed to inhibit the production of
disease-causing proteins. They can be designed to treat a wide range of diseases
including infectious, inflammatory and cardiovascular diseases and cancer and
have the potential to be more selective and, as a result, more effective and
less toxic than traditional drugs.
Apoptosis: Programmed cell death controlled by
genes that cause a cell to die at a specific time. Apoptosis can be brought
about by some drugs used to treat cancer.
(adaptamer): A type of synthetic oligonucleotide
that can bind to a particular target molecule, such as a protein or metabolite.
Arrayed library: Individual primary recombinant
clones (hosted in phage, cosmid, YAC, or other vector) that are placed in
two-dimensional arrays in microtiter dishes. Each primary clone can be
identified by the identity of the plate and the clone location (row and column)
on that plate. Arrayed libraries of clones can be used for many applications,
including screening for a specific gene or genomic region of interest as well as
for physical mapping. Information gathered on individual clones from various
genetic linkage and physical map analyses is entered into a relational database
and used to construct physical and genetic linkage maps simultaneously; clone
identifiers serve to interrelate the multilevel maps. Compare library, genomic
Aspiration: To draw out by suction.
Asymptomatic: Having no symptoms of disease. Many
cancers can develop and grow without producing symptoms, especially in the early
stages. Tests - such as mammograms - help find these cancers when chances for
cure are highest.
Atypical: Not usual. Often refers to appearance
of cancerous or precancerous cells. (See: hyperplasia.)
Autologous bone marrow transplantation: See bone marrow transplantation.
Autoradiography: A technique that uses X-ray film
to visualize radioactively labeled molecules or fragments of molecules; used in
analyzing length and number of DNA fragments after they are separated by gel
Autosome: A chromosome not involved in sex
determination. The diploid human genome consists of 46 chromosomes, 22 pairs of
autosomes, and 1 pair of sex chromosomes (the X and Y chromosomes).
Axillary dissection: Removal of the lymph nodes in the armpit (axillary nodes).
They are examined for the presence of cancer.