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Glossary

A glossary of terms.

Welcome to the CML Support glossary of technical terms. If you see a term anywhere on our site which you would like to see here, please Google the term and send us the explanation via our Contact us form so that we can add it.

Click one of the letters above to advance the page to terms beginning with that letter.

A

ABL1 search for term

A human proto-oncogene located on chromosome 9. The designation is taken from name of the scientist, Herbert Abelson MD, who discovered the gene. ABL1 activates a number of cell cycle-controlling proteins and enzymes. Mutations in the ABL1 gene are associated with chronic myelogenous leukaemia (CML).

Accelerated phase search for term

An intermediate phase between the initial chronic phase and the third blastic phase of the disease; typically lasting beteen 6 to 9 months with an increase in blast cells seen in both marrow and peripheral blood. Disease symptoms are more apparent.

Adherence search for term

The extent to which therapy is taken as prescribed. Good adherence to TKI therapy is known to have a direct impact on optimal response to treatment.

Allele search for term

One of two or more versions of a gene. We each two alleles for each gene, one version inherited from each parent.

Allogeneic Transplant search for term

Transplantation of cells taken from the bone marrow or stem cells taken from the peripheral blood of either a related or unrelated HLA matched donor.

ALP- Alkaline phosphatase search for term

An enzyme producted by the liver. High levels may indicate problems with liver function, however it is not specific to the liver and can be an indication of increased activity in the bone marrow caused by a high turnover of leukamic cells due to the effecs of therapy.

ALT search for term

An enzyme made in the liver, also called SGPT. Elevated levels may be a sign of liver toxicity (hepatotoxicity).

Anaemia search for term

Where the number of red blood cells (erythrocytes) is lower than normal, usually measured by a decrease in the amount of haemaglobin.

ANC search for term

Abbreviation for absolute neutrophil count.

Apoptosis search for term

The natural process of programmed cell death which rids the body of cells that are either at the end or their natural useful life or have been damaged beyond repair.

AST search for term

An enzyme made by the liver, sometimes called SGOT. Elevated levels may be a sign of liver toxicity (hepatotoxicity).

Autologous transplant search for term

A transplant using stem cells taken from your own blood or marrow.

Autosome search for term

Any single one of the numbered pairs of chromosomes apart from either of the sex chromosomes. Humans have 22 pairs of autosomes numbered roughly in relation to size.

B

Bands search for term

Immature neutrophils.

Basophil search for term

A type of white cell involved in inflammatory and allergic responses, elevated counts are thought to play a role in CML.

BCR search for term

A normal gene located at the 'breakpoint cluster region' on chromosome 22.

Bcr-Abl1 search for term

The protein transcribed by the BCR-ABL1 gene that signals for a continuous division of Ph+ cells. It displays high protein tyrosine kinase activity (this activity is due to the Abl1 half of the protein). The unregulated expression of Bcr-Abl1 activates other proteins that are involved in cell cycling and cell division.

Bilirubin search for term

A yellow fluid produced in the liver. Elevated bilirubin levels can cause a condition called jaundice in which the eyes and skin appear yellow, urine becomes very dark and feces are light. There are two measures of bilirubin: Total Bilirubin, which measures the amount of bilirubin in the bloodstream and Direct Bilirubin, which measures the amount of bilirubin made in the liver. Normal total bilirubin levels range from .20 mg/dL to 1.50 mg/dL. Normal direct bilirubin levels range from .00 mg/dL to .03 mg/dL

Blast Cells search for term

Immature cells such as myeoblasts and lymphoblasts develop into mature white blood cells. Represent about 1 to 5 % of normally developing marrow cells.

Blast Phase/Blast Crisis search for term

The third most severe phase of CML lasting from 3 to 6 months; characterized by high white cells count; decreased platelet count and the presence of more that 30% myeloblasts in peripheral blood, although in some cases there are a majority of lymphoid rather than myeloid blast cells.

Bone marrow search for term

A spongy tissue in the hollow central cavity of the bones where blood cells are formed from stem cells.

Bone marrow biopsy search for term

A method of removing a small sample of bone marrow from the body to have it examined under a microscope and possibly analyzed by other tests.

Bosulif search for term

The commercial name for bosutinib.

bosutinib search for term

A 3rd generation Tyrosine Kinase Inhibitor (TKI) effective in the treatment of Ph+CML.

C

Cancer search for term

A group of diseases characterized by uncontrolled cell growth.

Cancer Drugs Fund search for term

The Cancer Drugs Fund was established in order to provide a means by which National Health Service (NHS) patients in England could get cancer drugs that are not routinely available on the NHS.

CBC search for term

The number of white blood cells, red blood cells and platelets in the patient's sample of blood is determined.

CCyR search for term

Abbreviation of complete cytogenetic response when testing shows Ph+ cells have fallen below 1.5% in the marrow.

CDF search for term

The Cancer Drugs Fund was established in order to provide a means by which National Health Service (NHS) patients in England could get cancer drugs that are not routinely available on the NHS.

Centomere search for term

The central region of a chromosome separating it into a short arm (p- for petite) and a long arm (q- the next letter after p).

CHR search for term

Complete haematologic response; where Ph+ cells can no longer be detected in the peripheral blood.

Chromosome search for term

DNA is organized into long strands forming structures called chromosomes which reside in the nucleus of a cell. In the process of cell divison chromosomes duplicate providing each cell with its own complete set

Chronic Phase search for term

CML is characterized by two to three phases or stages. The first stage is called the Chronic Phase and usually lasts from 5 to 6 years. The vast majority of patients (85% to 90%) are diagnosed while in the Chronic Phase. Very often, individuals in the Chronic Phase have no or few symptoms and are diagnosed through a routine blood test. Some people in the Chronic Phase experience symptoms such as fatigue, shortness of breath, feeling of fullness or pain in the upper left side of the abdomen (due to enlarged spleen), weight loss, night sweats and anemia. Typical features of Chronic Phase are: elevated white blood cell (WBC) count; normal or high platelet count; increased basophil count; sometimes increased eosinophil count; and, most importantly, fewer than 15% myeloblasts. In the Chronic Phase, as in all three phases of CML, the marrow is usually hypercellular at diagnosis.

Clonal evolution search for term

Abnormal changes within the chromosome, often indicative of disease progression.

CML search for term

Chronic myeloid leukaemia, also known as chronic myelogeous leukaemia: a blood cancer arising from an acquired genetic abnormality in a progenitor cell (stem cell) which causes certain kinds of white cells to increase to abnormal levels in the marrow.

Conventional Cytogenetics search for term

Analysis by microscope of individual cells for the presence or absence of abnormal chromosomes (for example, the Philadelphia Chromsome). The process is very time consuming and is usually conducted on 20 marrow metaphase or dividing cells.

Conversion Factor search for term

The molecular response value determined by a particular (local) lab is determined to allow the labs qRT-PCR results to be converted to the International Standard or Scale (I.S.).

Cytogenetic Relapse search for term

An increase in the percentage above 1% of Ph+ cells in the blood and/or marrow.

Cytogenetic Response search for term

A reduction in the number of Ph+ cells evident in the blood and/or marrow.

Cytoplasm search for term

Liquid composed of water, salts and organic molecules that fills the inside of a cell.

D

dasatinib search for term

A second generation tyrosine kinase inhibitor used to treat Ph+ CML.

DESTINY search for term

The DESTINY trial evaluates the feasibility of de-escalation and then stopping treatment in chronic myeloid leukaemia patients with excellent responses to prior treatment.

DNA search for term

Deoxyribonucleic acid is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are known as polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of a nitrogen containing nucleobase, either guanine (G), adenine (A), thymine (T), or cytosine (C).

E

EFS search for term

Event free survival. A measure of the proportion of people who remain free of a particular complication of disease (called an event) after treatment that is designed to prevent or delay that particular complication.

ELNet search for term

European Leukaemia Network of expert Haemotologists.

Eosinophils search for term

A type of white blood cell involved in allergic responses and parasitic infections.

Erythrocytes search for term

Red blood cells.

F

FISH search for term

Common abbreviation for Fluoresence In Situ Hybridization. A method using DNA probes for determining many chromosomal abnormalities associated with CML by analyzing peripheral blood or bone marrow. FISH usually looks at standard 200 interphase cells, and is thus more sensitive than conventional chromosomal analysis. FISH does not look at dividing or metaphase cells.

G

generic search for term

A generic drug is a pharmaceutical drug that is equivalent to a brand-name product in dosage, strength, route of administration, quality, performance, and intended use. For CML, as of 2017 generic imatinib is available in several countries. Generic versions of other TKIs are not, at this time, routinely available.

Genes search for term

Carried in the DNA of every cell, genes hold all the information to build and maintain an organism and pass genetic traits to offspring. All organisms have genes corresponding to various biological traits, some of which are instantly visible (eye colour) some of which are not, (blood type). Derived from the Greek word genesis meaning “birth”, or genos meaning “origin”.

Genetic code search for term

The genetic code specifies the correspondence during protein translation between codons and amino acids. The genetic code is nearly the same for all known organisms.

Glitazones search for term

At the molecular level, glitazones stimulate peroxisome proliferator-activated receptors (PPARs), specifically PPARγ, a ligand-activated nuclear transcription factor that modulates the expression of the gene-regulated proteins which control glucose and lipid metabolism.

Glivec search for term

Brand name in Australia, Europe and Latin America for imatinib mesylate, the first generation tyrosine kinase inhibitor used in the treatment of Ph+CML as well as some other cancers; known as Gleevec in Canada, South Africa and the USA.

Graft versus Host Disease search for term

A condition that occurs following bone marrow or stem cell transplant in which the donor's immune cells, in the transplanted marrow, make antibodies against the host's (patient recipient’s) tissues.

GUSB search for term

A control or ‘housekeeping gene’ used by some labs in qRT-PCR testing.

H

Haemaglobin search for term

The red pigment in red blood cells their color. It functions to carry oxygen from the lungs to the rest of the body. The normal range for hemoglobin is 13 to 18 gm/dL for males and 11.5-16.5 gm/dL for females.

Haematocrit search for term

The hematocrit measures how much space in the blood is occupied by red blood cells. It is useful when evaluating a person for anemia. The normal range for hematocrit is 40.0% to 52.0%.

Haematopoiesis search for term

A continuous process of blood cell development from stem cells in the marrow. Stem cells differentiate into immature blood cells of various types. The immature blood cells develop into mature fully functional blood cells which enter the blood and circulate throughout the body. Most blood cells live for short periods and must be steadily replaced. Red cells die within four months, platelets within 10 days and most neutrophils in one to three days. About 100 billion blood cells are made each day.

HGB search for term

Abbreviation for haemaglobin.

HLA search for term

(Human Leukocyte Antigens) Typing - A blood test that determines a person's compatability for purposes of a bone marrow or stem cell transplant based on the types of antigens present.

Hydroxycarbamide search for term

A chemotherapy drug often used in newly diagnosed CML for an initial very short period before the start of TKI therapy in order to reduce high white cell counts; it does not have any cytogenetic effect on the disease.

Hypercellular search for term

In CML, refers to the fact that there is an overabundance of certain kinds of cells in the bone marrow. Hypercellular marrow is particularly common at diagnosis and early in the course of IM treatment in CML patients.

Hypocellular search for term

In CML, refers to the fact that there is an decreased number of certain kinds of cells in the bone marrow. Hypocellular marrow is particularly common with continued IM treatment in CML patients.

I

I.S. search for term

International Scale used for determining an internationally agreed standard of q RT-PCR molecular laboratory testing values.

Iclusig search for term

The commercial name for ponatinib.

IFN search for term

Abbreviation for Interferon Alpha.

Imatinib search for term

The generic name for Glivec or Gleevec (US); the first generation of tyrosine kinase inhibitors used to effectively treat and control Ph+CML.

Imatinib Mesylate search for term

The generic name for Glivec or Gleevec (US); the first generation of tyrosine kinase inhibitors used to effectively treat and control Ph+CML.

Interferon Alpha search for term

A protein found in humans encoded by the IFNA1 gene; sometimes used in the treatment of CML before the introduction of TKI therapy.

IRIS Study search for term

Abbreviation of the International Randomized Study of Interferon and STI571 (imatinib/Glivec). A study opened in 2000 - 2001 compared imatinib with interferon alpha and low-dose cytarabine for newly diagnosed chronic phase CML in 1,106 patients.

K

Karyotype search for term

The systematic arrangement of the 46 chromosomes in the human cell in 22 matched pairs (maternal and paternal member of each pair) by length from longest to shortest and other features, with the sex chromosomes (#23) shown as a separate pair (either XX or XY). The 22 pairs are referred to as autosomes.

L

Leukocytes search for term

White blood cells.

Liver Function Tests search for term

A group of blood tests that can help to show how well a person's liver is working. LFTs include measurements of albumin, various liver enzymes (ALT, AST, GGT and ALP), bilirubin, prothrombin time, cholesterol and total protein. All of these tests can be performed at the same time.

Log Reduction search for term

1 log reduction is a 10-fold (one decimal) or 90% reduction in numbers. A 3-log reduction is equivalent to a 1000-fold decrease.

M

Major Cytogenetic Response search for term

A reduction in the percentage of cells expressing the Philadelphia Chromosome to 35% or less in a CML patient.

Major Molecular Response search for term

Sigifying an optimal response to TKI therapy; also written as MR3 (3 log reduction from diagnosis) and/or 0.1% Bcr-Abl. (see MMR)

Minimal Residual Disease search for term

Small amounts of abnormal cells remaining, even when blood and marrow may appear to be normal; the amount residual cells can only be determined by molecular testing techniques such as qRT-PCR.

MMR search for term

Sigifying an optimal response to TKI therapy; also written as MR3 (3 log reduction from diagnosis) and/or 0.1% Bcr-Abl. (see Major Molecular Response)

Molecular Response search for term

Levels of response to therapy shown by q-PCR testing. MR3 to MR5 are equivalent to reductions in levels of Bcr-Abl1 from 0.1% (MR3) down to as low as 0.001% (MR5).

Molecular Targeted Therapy search for term

See TKI- tryrosine kinase inhibitor.

mRNA search for term

Messenger RNA: in CML the oncogene BCR-ABL1 duplicates as mRNA (Bcr-Abl1) which moves out of the nucleus into the cytoplasm where it translates as a signalling protein, a receptor tyrosine kinase which is constitutively active, leading to uncontrolled.

Myeloblasts search for term

An immature cell found in the bone marrow and not normally in the peripheral blood. Normally there are 0% myeloblasts in the peripheral blood and 0-5% blasts in the bone marrow.

Myelosuppression search for term

A decrease in the ability of the blood cell-producing tissues of bone marrow to produce all types of blood cells, especially neutrophils and platelets.

N

NCCN search for term

National Comprehensive Cancer Network (USA).

Neutropenia search for term

The condition of having abnormally low numbers of one type of white blood cell called neutrophils.

Neutrophil search for term

A type of white blood cell largely responsible for fighting infection. Normal range for neutrophils is 45.0% to 70.0%.

nilotinib search for term

A second generation tyrosine kinase inhibitor used to treat Ph+ CML.

Nucleus search for term

All cells apart from red cells have a nucleus in which chromosomes reside.

O

Oncogene search for term

Mutated gene that is a cause of a cancer. Several subtypes of acute myeloid leukaemia, acute lymphoblastic leukaemia and lymphoma and nearly all cases of chronic myeloid leukaemia are associated with an oncogene.

OS search for term

Overall survival. Indicates the proportion of people within a group who are expected to be alive after a specified time. Accounts for death due to any cause, both related and unrelated to the disease in question.

P

PCR search for term

qRT-PCR, quantitative reverse transcriptase (real time) polymerase chain reaction, a sensitive molecular test used to measure the ratio of BCR-ABL1 versus normal gene transcripts such as ABL1 or BCR.

Peripheral blood search for term

Blood that circulates throughout the body via the venous system.

PFS search for term

Progression free survival; a survival rate that measures the length of time either during or after treatment, during which the disease does not progress.

Ph+ search for term

Abbreviation for the Philadelphia chromosome.

Philadelphia Chromosome search for term

An abnormal shortened chromosome 22 found in the marrow and blood cells of patients with chronic myeloid leukaemia and a small proportion of patients with acute lymphoblastic leukaemia. First described in 1960 by Peter Nowell from University of Pennsylvania School of Medicine and David Hungerford from the Fox Chase Institute for Cancer Research and named after Philadelphia.

Platelets search for term

A type of blood cell that controls bleeding through a clotting mechanism.

ponatinib search for term

A third generation TKI - currently the only TKI therapy effective against the multi-drug resistant mutation known as T315i.

Proteins search for term

Products of genes produced in the cytoplasm of the cell, they signal for a variety of processes including cell division, proliferation and cell death (apoptosis).

Proto-oncogene search for term

A normal gene such as ABL1, that has the capacity to transform into an oncogene with increased cancerous activity, by a relatively small modification of its original function, such as the translocation event of chromosomes 9 and 22 in CML.

Pulmonary oedema search for term

Edema (Americn English) or oedema (British English is the accumulation of fluid in the air spaces of the lungs.

Q

QRT-PCR search for term

qRT-PCR, quantitative reverse transcriptase (real time) polymerase chain reaction, a sensitive molecular test used to measure the ratio of BCR-ABL1 versus normal gene transcripts such as ABL1 or BCR.

Qualitative PCR search for term

A PCR test used to either confirm or deny the presence of BCR-ABL1 gene transcripts in a blood or marrow sample.

R

Red Blood Cells search for term

Non nucleated cells that carry oxygen throughout the body.

Reference range search for term

The lower and higher end of values considered normal for a laboratory test. All laboratory results which show counts at the lower or higher ends, or anywhere in between, are considered normal.

RNA search for term

A second type of nucleic acid that is similar to DNA. The expression of genes encoded in DNA begins by their duplication into RNA molecules. RNA is less stable than DNA and is typically single-stranded.

S

SCT search for term

Abbreviation of stem cell transplant; a procedure which replaces the stem cells of the recipient with those of an HLA matched donor in the hope of curing the disease.

SMC search for term

Scottish Medicines Consortium

Spleen search for term

A large organ to the left of the stomach and below the diaphragm, serving to store blood, disintegrate old blood cells, filter foreign substances from the blood, and produce lymphocytes(white blood cells). An enlarged spleen is a common finding at CML diagnosis.

Sprycel search for term

The commercial name for dasatinib.

Stem Cell search for term

Called blood stem cells or haematopoietic stem cells, are primitive cells found in the bone marrow from which all types of blood cell develop.

T

Tasigna search for term

The commercial name for nilotinib.

Thrombocytopenia search for term

The condition of having abnormally low numbers of platelets.

Thrombocytosis search for term

The condition of having abnormally high numbers of platelets.

TKI search for term

Tyrosine Kinase Inhibitor (TKI), a molecular targeted therapy designed to block specific proteins that cause leukaemic cells to divide. Imatinib was the first generation in this class of oral therapy; dasatinib, nilotinib, bosutinib and ponatinib are second generation TKIs now used as 1st, 2nd, 3rd and 4th line therapy.

Translocation search for term

An event that occurs when part of one chromosome breaks off and attaches to a different chromosome. In 1973, Janet D. Rowley at the University of Chicago described the mechanism by which the Philadelphia chromosome arises as a reciprocal translocation between chromosomes 9 and 22.

Tyrosine kinases search for term

proteins that play a key role in cell signalling processes.

W

Whte blood cells search for term

Also known as Leukocytes, these kind of cells are part of the immune system helping to fight infections and other diseases. There are three major types; monocytes, lymphocytes and granulocytes.