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Glossary of Important Terms

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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

Anemia: when red blood cell counts are lower than normal

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BCR-ABL: an abnormal protein that causes out-of-control production of CML cells

BCR-ABL transcripts: signals that tell your cells to produce more BCR-ABL proteins

Blast cell: an immature white blood cell that does not function properly

Blast phase CML: the final and most serious phase of CML; symptoms become more severe and are more difficult to treat

Bone marrow: the soft tissue inside bones that produces blood cells

Bone marrow aspiration: a thin, hollow needle is used to draw a small amount of liquid bone marrow. The sample is usually taken from the hipbone at the same time a bone marrow biopsy is performed

Bone marrow biopsy: a needle (slightly larger than the one used for aspiration) is used to draw a sample of bone and marrow. The sample is usually taken from the hipbone at the same time a bone marrow aspiration is performed

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Chronic myeloid leukemia (CML): a slow-developing cancer of the 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

Complete blood count (CBC): a blood test that counts the number of white and red blood cells, platelets, and other blood components

Complete cytogenetic response (CCyR): when cells carrying the Philadelphia (Ph) chromosome are undetectable

Complete hematologic response (CHR): when blood cell counts return to normal, there are no immature cells in the blood, and the spleen returns to normal size

Complete molecular response (CMR): when the number of BCR-ABL transcripts is reduced to undetectable levels

Conventional cytogenetic testing: a test that counts the number of Ph chromosomes in your blood, but is not very sensitive; requires bone marrow sample

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Fluorescence in situ hybridization (FISH): a highly accurate and sensitive test that counts the number of Ph chromosomes in your blood; may use either blood or bone marrow sample

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Hematologic testing: a blood test that counts the number of white blood cells (WBCs), red blood cells (RBCs), and other types of cells in your blood. Usually referred to as a CBC

Hemoglobin: your hemoglobin count measures the ability of your red blood cells to carry oxygen. A normal hemoglobin count is 14 to 17 for men and 12 to 16 for women. Most people still feel well with a hemoglobin count as low as 10

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Intolerance: when a person has severe, bothersome side effects caused by medication that impair the ability to carry on normal daily activities

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Leukemia: several acute (progresses quickly) or chronic (takes a longer time to progress) diseases of the blood and bone marrow; characterized by an abnormal increase in blood cells

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Major cytogenetic response (MCyR): when the percentage of cells carrying the Philadelphia (Ph) chromosome is 0% to 35% (this combines both complete and partial responses)

Major molecular response: when the number of BCR-ABL transcripts is reduced 3 logs (approximately 1000-fold reduction)

Molecular response: when there is a reduction in the BCR-ABL transcripts detected during your molecular test

Molecular testing: a test designed to count the number of BCR-ABL transcripts in the blood; it is often referred to as quantitative polymerase chain reaction

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

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Neutropenia: when white blood cell levels are lower than normal

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Partial cytogenetic response: when the percentage of cells carrying the Ph chromosome is reduced to 1% to 35%

Philadelphia (Ph) chromosome: the chromosome abnormality that causes CML; pieces from two different chromosomes break off and fuse together to create this new, abnormal chromosome

Platelets: blood cells that help stop bleeding. When platelet levels are lower than normal, it is called thrombocytopenia

Protein: a large molecule within human cells required for the body to function properly; each protein has unique functions

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Quantitative Polymerase Chain Reaction (QPCR) testing: see Molecular testing

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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

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Side effect: the undesired, negative effects of a drug

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Thrombocytopenia: when platelet levels are lower than normal

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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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