Glossary of CML Terms

A

Accelerated phase CML
the second phase of CML; leukemic cells grow more quickly and symptoms such as weight loss, fever, and poor appetite may occur
Acute leukemia
grows faster than chronic leukemias. There is a rapid buildup of immature, functionless cells in the marrow and blood. The marrow often halts production of normal red blood cells, white cells, and platelets
Anemia
a condition where red blood cell counts are lower than normal

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B

BCR-ABL gene
abnormal gene that causes CML
BCR-ABL protein
an abnormal protein that causes out-of-control production of CML cells
BCR-ABL transcripts
signals created by CML that tell your cells to produce more BCR-ABL proteins
Blast cell
an immature white blood cell that does not function properly in patients with CML
Blast crisis
a serious condition that occurs in CML when you have 20% or more blast cells, accompanied by fever, fatigue, and an enlarged spleen
Blast phase CML
the final and most serious phase of CML; symptoms become more severe and are more difficult to treat
Bone marrow
soft, spongy tissue that fills the large bones and makes blood cells
Bone marrow aspiration
the removal of a small amount of liquid bone marrow for counting the leukemic Ph+ cells. It uses a thin, hollow needle
Bone marrow biopsy
the removal of bone marrow tissue from inside bone, also to evaluate leukemic Ph+ cells. The needle used is slightly larger than that used for aspiration

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C

Cancer
when abnormal cells divide without control and invade nearby tissues
Chemotherapy
drugs that can kill cancer cells, slow their growth, and prevent them from spreading to other parts of the body. May be used after cancer surgery to keep cancer from coming back
Chromosome
rod-shaped or threadlike structure that contains DNA and the genes
Chronic leukemia
a blood cancer in which there is a slow buildup of immature, functionless cells in the marrow and blood. Because progress is slower, greater numbers of mature, functional cells may continue to be made
Chronic myeloid leukemia (CML)
a slow-developing cancer of the bone marrow and blood in which the body produces an uncontrolled number of abnormal blood cells
Chronic phase CML
the first phase of CML; it can last for months or years; most people are diagnosed with CML during this phase
Clinical trial
a research study designed to improve current treatments, or to gather information on the safety and effectiveness of experimental CML treatments
Complete blood count (CBC)
a CML blood test that counts the number of white and red blood cells, platelets, and other blood components
Complete cytogenetic response (CCyR)
occurs in the treatment of CML when cytogenetic testing is unable to detect the Philadelphia (Ph) chromosome in bone marrow or blood cells (0% Ph+ cells)
Complete hematologic response (CHR)
occurs in the treatment of CML when blood cell counts return to normal, there are no immature cells visible in the blood, and the spleen returns to normal size
Complete molecular response (CMR)
occurs in the treatment of CML when the number of BCR-ABL transcripts is reduced to levels undetectable by molecular testing
Cytarabine
a chemotherapy drug that causes a decrease in red blood cells. It resembles a normal cell nutrient needed by cancer cells to grow. The cancer cells take up cytarabine, which then interferes with their growth
Cytogenetic testing
tests that identify the presence of the Philadelphia chromosome in blood or bone marrow cells of CML patients

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D

Deoxyribonucleic acid (DNA)
the hereditary material in cells of humans and most other organisms
DNA
see Deoxyribonucleic acid

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F

Fluorescence in situ hybridization (FISH)
a highly accurate and sensitive CML test that counts the number of cells with BCR-ABL genes; may use either blood or bone marrow sample

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H

Hematologic testing
blood tests used with CML patients that count the numbers of red blood cells (RBCs) and platelets, as well as the types and numbers of white blood cells (WBCs); cells are also examined to determine whether or not immature blood cells (blast cells) are present
Hydroxyurea
a chemotherapy drug that treats cancer by stopping or slowing the growth of cancer cells

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I

Incidence
the number of newly diagnosed cases of a disease during a specific time period
Interferon
once a primary treatment for CML, this medication may be used after a stem cell transplant or after several other treatments have been tried
Intolerance
occurs when a person has severe, bothersome side effects caused by medications that impair the ability to carry on normal daily activities

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L

Leukemia
several acute (progresses quickly) or chronic (takes a longer time to progress) diseases of the blood and bone marrow such as CML; characterized by an abnormal increase in blood cells
Log reduction
each "log" means you have 10 times fewer molecular signals than at your first molecular test. Called BCR-ABL transcripts, the signals tell your cells to produce BCR-ABL proteins. The greater the log reduction, the greater the reduction of BCR-ABL transcripts in your body.

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M

Major cytogenetic response (MCyR)
occurs in the treatment of CML when the percentage of cells carrying the Philadelphia (Ph) chromosome is 0% to 35% (this combines both complete and partial responses)
Major molecular response (MMR)
occurs in the treatment of CML when the number of BCR-ABL transcripts is reduced by at least 3 logs (approximately 1000-fold reduction)
Molecular testing
a CML test designed to count the number of BCR-ABL transcripts in the blood; it is often referred to as quantitative polymerase chain reaction (QPCR)
Mutation
damage or change to DNA that involves a gene or a chromosome
Myeloid
having to do with bone marrow; also refers to cells that form blood and are found in bone marrow. May also be called myelogenous. Both are used to describe CML

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N

Neutropenia
having an abnormally low number of white blood cells, which help the body fight infection

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O

Oncologist
a physician who is a cancer specialist. A hematologist-oncologist is a physician specializing in cancers of the blood

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P

Partial cytogenetic response
occurs in the treatment of CML when the percentage of cells carrying the Ph chromosome is reduced to 1% to 35%
Philadelphia chromosome (Ph)
formed when pieces from two different chromosomes break off and fuse together to create a new, abnormal chromosome linked to CML. The new chromosome contains the abnormal BCR-ABL gene that signals cells to make too many white blood cells
Platelets
blood cells that help stop bleeding. When platelet levels are lower than normal, it is called thrombocytopenia
Polymerase chain reaction (PCR)
a sensitive test that can detect very small amounts of the BCR-ABL gene in blood or bone marrow samples. PCR can be used to help diagnose CML and, after treatment, to see if leukemia cells are still present
Prevalence
the number of persons alive who have a certain trait, condition, or disease
Prognosis
a prediction of the course and outcome of a disease, or the likelihood of recovery

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Q

Quantitative polymerase chain reaction (QPCR) testing
see Molecular testing

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R

Red blood cells (RBCs)
blood cells that carry oxygen to all parts of the body. When red blood cell counts are lower than normal, it is called anemia
Resistance
when cells are able to survive and grow, even when they are exposed to drugs that would normally kill them or limit their growth
Risk factor
an occurrence or characteristic that has been connected with the increased rate of a disease

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S

Side effect
the undesired, negative effects of a drug
Stem cells
cells from which other types of cells develop or are repaired or replenished. For example, blood-forming stem cells in bone marrow make red cells, white cells, and platelets
Stem cell transplantation
the only treatment that provides a potential cure for CML, but it is not an appropriate treatment for all patients. The patient receives high doses of chemotherapy to reduce the number of leukemia cells, followed by an infusion of blood-forming stem cells donated by another person who has a nearly identical tissue type (either a family member or an unrelated donor)

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T

Treatment goals
See Complete cytogenetic response (CCyR); Complete hematologic response (CHR); Complete molecular response (CMR); Major cytogenetic response (MCyR); Major molecular response (MMR)
Thrombocytopenia
when platelet levels are lower than normal
Tyrosine kinase inhibitors (TKIs)
these oral medications inhibit the BCR-ABL gene that causes the body to make leukemia cells

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W

White blood cells (WBCs)
blood cells that help fight infection. When the level of a certain type of white blood cell is lower than normal, it is called neutropenia

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