Listed below are
definitions of many terms which relate to cancer and its treatment.
We have selected these terms for you because they are the ones you
probably will encounter most frequently.
The terms are explained in a way that is relevant to most cancer
patients. If the term you are
seeking does not appear below, you can click on the following highlighted
link to the National Cancer Institute's
Dictionary of Cancer Terms.
This will take you to NCI web pages which contain definitions of more
than 4000 words and terms related to cancer, including many which are highly
technical. Clicking on this
link will take you out of the Weisenthal Cancer Group website.
To remain within the Weisenthal Cancer Group website, simply scroll
down the page to find the term you are seeking.
Allogeneic bone marrow
transplant: An infusion of bone
marrow or stem cells that were obtained from an HLA compatible donor.
This differs from an autologous bone marrow transplant in which
marrow or stem cells are obtained from the same patient into which they are
later reinfused.
Alopecia:
Alopecia means hair loss. Cells
responsible for hair growth divide more frequently than many other types of
cells in the body. Many
anti-cancer drugs work by targeting rapidly dividing cells.
This is because it is during cell division that cells of all kinds
are the most vulnerable to injury.
The extent of hair loss is related to the type and dosage of the drug
or drugs used and the number of cycles received.
Hair that is lost due to exposure to chemotherapy drugs generally
grows back at a normal pace once chemotherapy is stopped.
Anemia:
This is another case of rapidly dividing cells being the most vulnerable to
some types of anti-cancer drugs.
Many types of anti-cancer drugs work by targeting cells that divide
rapidly. Anemia means that
fewer red blood cells are available to carry oxygen throughout the body.
A person with anemia often feels fatigued.
Anemia can also be caused by suppression of stem cells in the bone
marrow caused by other types of cells such as leukemia cells, which divide
and reproduce themselves out of control.
Antiemetic:
An anti-emetic is a drug that is prescribed to help control nausea, which
can be caused by certain chemotherapy drugs.
Autologous bone marrow
transplant:
A small quantity of a patient's own bone marrow or stem cells are
removed before receiving high-dose chemotherapy, which is intended to kill
cancer cells in the patient’s body.
The marrow or stem cells are then reinfused into the patient after
the chemotherapy drugs are cleared from the body.
This allows the bone marrow to replenish itself.
Biopsy:
Removal of a sample of tissue from a patient in order to examine it
under a microscope or to perform
laboratory testing.
There are several types of biopsies.
Three of the most common types are:
Fine needle aspiration (FNA) - a small gauge needle is inserted into
the tumor, often guided by CT scan or ultrasound, and cells are withdrawn.
If a larger gauge needle is used, the procedure is called a needle core
biopsy. An excisional biopsy is a procedure in which a surgeon makes an
incision into the skin and removes the whole tumor mass. This differs from
an incisional biopsy in which only a small portion of the tumor is removed.
Blind studies:
In a single-blind study, patients are assigned to a study group (also called
an “arm”) in which all members receive either a research treatment, a
"standard-of-care" treatment, or, in some cases, a placebo – however the
patient does not know to which group (or arm) of the study they have been
assigned. In a double-blind study, neither the patient nor the doctor knows
which study group the patient is in. The intent is to minimize the chance of
bias in judging the effects of the treatment.
Most patients enter clinical trials hoping that they will receive the
new, investigational treatments but in single and double-blind studies this
often is not the case.
Blood Transfusion:
A transfusion is the replacement of blood or a blood component. A needle is
inserted into a vein and a tube carries replacement blood into the body.
A transfusion might be required to replace red blood cells or some
other blood component lost due to surgery, cancer treatment, or due to the
illness itself.
Bone marrow aspiration:
Removal of cells from the bone marrow.
Bone marrow is located inside of some of the larger bones of the
body. Red blood cells, white
blood cells, and platelets are produced in the bone marrow.
In a bone marrow aspiration, a doctor usually numbs the skin with a
local anesthetic and inserts a small gauge needle into the hip or, in some
cases, the sternum. The doctor
then draws back on a syringe to remove a small quantity of cells, which are
examined for abnormalities. A
bone marrow aspiration is performed to diagnose illness, perform laboratory
tests, or to monitor response to therapy.
Bone Marrow Biopsy:
A bone marrow biopsy is similar to a bone marrow aspiration (see above)
except that a larger gauge needle is used to obtain a small disk of bone
along with a sample of bone marrow.
Bone Scan:
This is a test that is used to see if cancer has spread to the bones. A
harmless radioactive tracer is injected and concentrates in abnormal cells
that are present in bones. These areas can then be detected.
Cancer cells are not the only abnormal cells that might be found in
bones. For example, arthritis
and infections are among other types of cells that can also cause the tracer
to concentrate.
Brachytherapy:
Brachytherapy is a form of radiation treatment in which radioactive
“seeds” are placed inside the body, as close to the cancer as possible.
Brachytherapy allows for continual exposure of cancer cells to
radiation and also spares overlying tissues from radioactive beams which
must pass through to reach the tumor site.
Bronchoscopy:
A bronchoscopy involves the use of a pliable fiber-optic filament
which is attached to a camera to allow viewing of the throat and lungs. If
a suspicious mass is found, a small biopsy can also be obtained during the
bronchoscopy.
Cancer:
The term cancer encompasses literally hundreds of different illnesses which
involve abnormal cells. The
three principal defining features of a cancer cell that make it different
from other types of normal and abnormal cells are that 1.) cancer cells have
the ability to grow out of control, 2.) to spread to other parts of the body
(metastasize) and 3.) to erode through membranes and thereby invade into
other tissues. In contrast, a
benign tumor has only one of these three properties.
A benign tumor certainly can grow in an uncontrolled fashion but it
does not travel to other parts of the body and, although it can crowd other
tissues and even damage them in the process, a benign tumor does not
actually invade into the other tissues or organs.
Carcinoma in situ:
A name given to a cancer that has not spread to other parts of the
body or invaded nearby tissue.
Cardiac Toxicity:
Some chemotherapy drugs, principally those in a class of drugs called
anthracyclines, can cause permanent damage to the heart.
Therefore, these drugs are given in carefully planned dosages and the
patient’s heart is monitored for signs of change.
Chemotherapy:
A type of cancer treatment that involves the use of drugs to kill cancer
cells or to stop them from growing.
Chemotherapy generally is used for cancers that have spread locally
or to distant sites in the body.
Adjuvant chemotherapy is used in certain cases where no additional
cancer is visible after surgery but chemotherapy is given anyway, just in
case the cancer has spread or some cancer cells have been left behind but
have not been detected.
Neoadjuvant chemotherapy is sometimes used prior to surgery in order to
shrink a tumor mass to the point where a less extensive surgical procedure
can be used. Drugs used for
adjuvant chemotherapy are often the same drugs that are used for primary
chemotherapy.
Clinical trials:
Clinical trials are used to test the effectiveness of new treatments.
In Phase I trials of chemotherapy drugs, maximum drug safe dosages
for humans are established and short term side effects are noted.
Most frequently, healthy volunteers are recruited into Phase I trials
but sometimes cancer patients are also accepted into the studies.
In Phase II trials, a small number of patients participate – perhaps
one or two hundred - and drug effectiveness and a therapeutic range of drug
dosages are noted. Phase III
clinical trials are large-scale, multi-institutional studies in which a new
drug must prove that it is more effective than existing treatments or at
least equally effective, with acceptable toxicities.
Phase IV trials are conducted after a drug has already received FDA
approval for use in a certain group of patients.
The idea is to see if the drug is effective for patients in other
clinical settings or to see how combining the drug with other drugs affects
the drug’s therapeutic benefit.
Additional information about side effects also is collected.
Colony Stimulating Factors:
These are drugs that boost the production of various blood components
in order to replace those which are depleted by illness or by treatment with
certain chemotherapy drugs.
Creatinine:
Creatine is excreted in urine where it can be easily measured as an
indicator of kidney function. Creatinine “clearance” is measured to
determine if a patient has underlying kidney problems or to monitor a
patient for potential damage to the kidneys from chemotherapy.
CT Scan (Computerized
Tomography):
The CT scan is an x-ray procedure that works by taking a series of
cross-section photos of the body.
Cycle:
Most chemotherapy drugs are administered only once every two or three
weeks in order to allow the body to recover from harmful side effects such
as the depletion of red and white blood cells, although some drugs are given
in an oral daily dose. Each
separate drug administration combined with it’s recovery period is called a
cycle
Edema:
Swelling caused by an abnormal accumulation of fluid in a limb,
organ, or other body tissue.
EGFR:
Epidermal Growth Factor Receptor.
A protein molecule involved in normal and abnormal cell growth.
In a healthy cell, EGFR signaling helps to perform a variety of
useful functions such as regulating normal cell growth, facilitating wound
healing, and helping to resist damage from toxins.
However, abnormal signaling along the EGFR pathway has been
associated with numerous dangerous cell behaviors such as tumor growth and
progression, metastasis, resistance to chemotherapy, and generally poorer
patient prognosis. A promising
area of chemotherapy research involves developing drugs that interfere with
EGFR activity and therefore prevent the type of
abnormal cell growth that is associated with cancer cells.
Endoscopy:
A small incision is made through the skin and a flexible tube
containing a video camera is inserted.
The doctor then can visualize a nodule or mass and perform a biopsy
if necessary while viewing the procedure on a video monitor.
Endothelial Cell: Endothelial cells form capillaries in a process called angiogenesis. Capillaries carry oxygen and nutrients to tumor cells. A new class of drugs, called angiogenesis inhibitors, targets these endothelial cells. This starves tumor cells of oxygen and nutrients, interferes with the elimination of cellular wastes, shuts-down routes of tumor metastasis, and potentially aids in the delivery of other types of anti-cancer drugs to the tumor mass.
Extravasation:
This describes a condition which occurs during infusional
chemotherapy when a chemotherapy agent leaks from a vein into local tissue,
causing damage to the vein and potentially also to the surrounding tissues.
Functional Tumor Cell
Profiling:
This is a laboratory method in which living tumor cells are obtained
from individual cancer patients and are exposed to different chemotherapy
drugs in order to see which of the drugs are effective at killing or
stopping the growth of the cancer cells and which of the drugs are not
effective. The purpose of
Functional Tumor Cell Profiling is to personalize therapy design by
identifying chemotherapy drug treatments that have the greatest likelihood
of helping each patient as an individual.
This is the opposite of empirical therapy selection in which patients
are treated blindly with drugs that worked in the past for some percentage
of patients who received them.
Functional Tumor Cell Profiling is based upon the principle that no cancer
patient is "average" but rather that each patient's illness is unique in its
response to treatment. This is
supported by the clinical observation that different cancer patients often
respond very differently to the same treatments
Gallium Scan:
A method for detecting cancer in which a radioactive tracer is
injected into a vein and is then visualized to see if the tracer accumulates
in a certain area of the body, potentially indicating the presence of a
tumor in that area.
Informed consent:
A legal document that outlines the aims, methods, and risks of a
procedure or research study. A patient who signs an informed consent is
indicating that he or she agrees to participate in a study or to undergo a
procedure in spite of possible risks.
Infusion:
Delivering drugs or other fluids into the body by means of a needle
which is inserted into a vein.
The needle may be attached to a syringe or to a tube which leads to plastic
bag in which the fluid is contained.
Institutional review board
(IRB):
A panel of persons who must first approve and then monitor any
clinical trial which includes human subjects in order to ensure the safety
and privacy of patients who participate.
Intravenous (IV):
The introduction of fluids into the body by means of injection into a
vein.
Lymph nodes:
These are small glands or sacks that are scattered throughout the
body. Lymph fluid passes through the lymph nodes carrying infections and
impurities, which are then trapped in the lymph node where they can be
attacked by white blood cells.
Cancer cells are often carried in lymph fluid and spread to other parts of
the body through the lymphatic system.
Therefore, doctors often examine lymph nodes for signs of
cancer.
Lymphedema:
An accumulation of lymphatic fluid in tissues, resulting in swelling.
Malignant:
A term used to indicate the presence of cancer, such as a malignant
tumor. The term “malignancy”
can refer to a tumor mass, a cancerous cell, or a general or specific type
of cancer.
Mediastinoscopy:
An flexible tube is passed through a small incision at the base of
the neck and directed behind the sternum into the chest cavity.
This allows for visualization of a suspicious mass and the taking of
a biopsy for study.
Metastasis:
A cancer which has spread from the point of origin to another part of
the body. A cancer may spread
“locally”, generally meaning into surrounding tissues, “regionally”,
generally meaning to not-too-distant structures such as lymph nodes, or else
the spread may be “distant,” meaning to remote parts of the body.
MRI (Magnetic Resonance
Imaging):
MRI is similar to a CT scan but uses magnetic fields instead of
radiation to visualize internal body structures. MRI scans can take longer
to perform but provide greater detail than CT scans.
Mucositis:
Occurs when chemotherapy damages epithelial cells
which line the mouth and esophagus.
The feeling is one of general soreness to these surfaces.
Topical anesthetics may be given, including a viscous liquid which is
gargled and produces temporary relief.
Mucositis is a temporary condition.
The cells usually replenish themselves and the soreness goes away
within a few days.
MUGA Scan:
A MUGA Scan is performed to assess heart function.
It might be performed prior to starting chemotherapy or while therapy
is in progress, to monitor heart function and see if changes are occurring.
MUGA scanning involves injecting a radioactive tracer that is tracked
with a special scanner as it passes through the heart.
Nadir:
The lowest point in the white blood cell count reached after
chemotherapy. Generally, it
occurs around 7-14 days following drug administration, depending on the
drugs and dosages given.
Patients generally are most susceptible to infections when white counts are
near their nadir.
Neoadjuvant Chemotherapy:
See the definition under Chemotherapy.
Neoplasm:
An abnormal, usually unregulated, proliferation of cells. A neoplasm
can be malignant or benign. Cancer is often described as a “malignant
neoplasm”.
Neutropenia:
An abnormally low neutrophil count.
A neutrophil is a type of while blood cell that helps to fight
infections. Neutrophils are often depleted by cancer chemotherapy drugs and
must be monitored throughout treatment.
Oncologist:
A doctor who specializes in cancer treatment.
A medical oncologist specializes in planning and administering
chemotherapy treatments. A
radiation oncologist treats tumors by exposing them to x-rays.
A surgical oncologist specializes in removing tumors surgically.
A gynecologic oncologist specializes in women’s reproductive cancers
and combines certain attributes of both a surgical oncologist and a medical
oncologist.
Oncology:
A medical discipline that focuses on the study and treatment of
cancer.
Performance Status:
A relative scale doctors often use to describe a patient's overall
physical well-being, based upon his or her ability to do everyday tasks such
as sitting upright for long periods, walking, and performing other normal
activities. Clinical trials
often specify a minimum performance status level for entry in order to make
sure that patients are well enough to receive certain chemotherapy drugs
given at necessary dosages.
PET Scan (Positron Emission
Tomography Scan):
In a PET scan, a radioactive tracer which has been chemically bound
to glucose - a form of sugar - is injected into a vein.
Cells use higher amounts of glucose when they are actively dividing
and reproducing themselves.
Because a tumor contains large numbers of actively dividing cells, much of
the glucose is absorbed by cells clustered in a small area.
A PET scan looks for tumors by detecting areas in organs, lymph nodes
and other parts of the body where the radioactive glucose has concentrated.
Port-A-Catheter:
A port-a-catheter makes it easier to give chemotherapy when multiple
drug infusions, spread over several weeks or months, are anticipated. The
small plastic or steel port is inserted just under the skin of the chest or
arm by a simple, outpatient procedure. The port-a-catheter has a small tube
that remains connected to a nearby vein.
Then, instead of repeatedly having to locate and puncture a vein in
order to administer each cycle of chemotherapy, the drugs are introduced
into the catheter with less discomfort to the patient.
Prognosis:
A patient’s most likely clinical outcome based upon a variety of
factors specific to the patient combined with what is generally known about
the usual behavior of a certain type of cancer.
Protocol:
A formal study plan consisting of guidelines and rules that must be
strictly followed in the course of a clinical trial.
Randomized trial:
A type of clinical trial in which patients are randomly assigned to
receive different treatment regimens.
Recurrence:
The return of a cancer that previously was in remission.
Red blood cell:
Red blood cells are produced in the bone marrow. They circulate in
the blood and carry oxygen to cells throughout the body.
Refractory:
A disease which is not responsive to treatment.
Regimen:
A chemotherapy plan - it includes drugs, dosages, and treatment
scheduling.
Relapse:
A disease recurrence following initial treatment success.
Remission:
Similar to response (see below).
It refers to a partial or complete disappearance of detectable cancer
or the reduction or disappearance of disease symptoms.
Response:
This has a very specific meaning in cancer treatment.
In order to say that a response has occurred, a tumor mass must have
shrunk by at least 30% in its perpendicular dimensions (height and width) in
comparison with it's original
size, when measured by some objective means, such as x-ray.
If a tumor has shrunk by less than 50% it is called a partial
response. If there is no
evidence of disease following treatment it is called a complete response.
A less technical but still measurable way of evaluating response is
to detect proteins circulating in the blood, called tumor markers, that
correlate with improving or worsening illness.
An imprecise but highly practical method of evaluating treatment
response is to note if there is an improvement in symptoms of disease.
Response does not mean the same thing as a cure and, in fact,
response is not even a reliable predictor of overall survival time.
However, response to treatment clearly is a good thing and it is the
first criterion upon which a physician determines whether or not a treatment
is working. A treatment that
does not produce a response in a specific patient will be discontinued.
Single agent:
Single-agent chemotherapy is the use of a single chemotherapy drug
for the treatment of cancer.
Splenomegaly:
An enlarged spleen.
Stable Disease:
A condition in which a cancer is becoming neither better or worse.
For a solid tumor type it may mean that a tumor is neither shrinking
nor growing. For a leukemia or
other hematologic cancer it may mean that the circulating cancer cell
population is neither increasing nor decreasing.
Stage:
Staging is a method of determining the extent of the cancer, or how
far the disease has spread. The stage is determined after performing a
series of diagnostic tests, which may include x-rays, scans, and sometimes
surgery.
Stem cell:
An immature cell that has the ability to develop into any of several other
types of cells, notably red or white blood cells or platelets.
Most stem cells are found in the bone marrow, but a small number,
called peripheral stem cells, circulate in the blood.
Thrombocytopenia:
Some anti-cancer drugs and also some cancers themselves can suppress
the bone marrow, in which platelet cells are produced.
Platelets are necessary for blood clotting.
Platelets have a fairly short life span and must be replaced about
every 10 days. Thrombocytopenia
is a condition in which platelet levels are reduced because platelets have
died and cannot be replaced owing to bone marrow suppression.
Toxicity:
Toxicity refers to the potential of a drug to produce harmful side
effects. Most drugs have known
toxicities. That is, they are
known to produce specific types of side effects.
When combining chemotherapy drugs, care must be taken to avoid
administering two or more drugs with severe overlapping toxicity profiles.
Tumor markers:
Proteins circulating in the blood that that are known to be produced
by specific types of cancer. These can be detected and measured using
laboratory techniques. More
meaningful than static measurements of tumor markers are serial measurements
over time which might indicate that the number of cancer cells in the body
are increasing or decreasing.
This can be useful as an indicator of whether a cancer is responding or not
responding to therapy.
Tyrosine Kinase:
An enzyme involved in communication within cells, or signaling
pathways. Abnormal tyrosine kinase signaling can cause dangerous cell
behaviors such as unregulated cell growth.
Tumor:
A tissue mass generally containing a mixture of both mutated and
normal cells. Some cells in the
tumor may be necrotic (dead) and others may be viable (living).
A tumor, also sometimes called a "lesion" a "mass" or a "neoplasm,"
may be malignant or benign. It
takes about one billion cells to form a tumor mass that is one centimeter in
diameter.
Ultrasound:
An imaging technique in which high-frequency sound waves are used to
create pictures of internal structures.
Vesicant:
A chemotherapy drug that could potentially cause serious tissue
damage if it leaked from the a vein into surrounding tissues.
A drug that is capable of causing a somewhat less severe reaction if
leaked is called an irritant.
White blood cell: White blood cells are immune cells, so-called because they are instrumental in fighting infections. When white blood cells are depleted, such as by certain chemotherapy drugs, or are not functioning properly, as in some cancers of the blood, the body is highly susceptible to infectious illnesses.
