What is CML?
CML stands for Chronic Myelogenous Leukemia.
What do those words mean?
- Chronic: A persistent condition or illness that continues over a long time, or a disease or condition that develops very slowly. This is different from an “acute” disease that has a sudden onset, sharp rise, and short course. 1
- Myelogenous: Of, relating to, originating in or produced in the bone marrow (the soft centre of bones). 2
- Leukemia: A disease involving an abnormal increase in the number of white blood cells in the tissues of the body with or without an increase of those in the circulating blood, and is classified according to the type of white blood cell most prominently involved. 3
So, in short, CML is a persistent disease resulting from the bone marrow producing too many white blood cells.
CML is sometimes also called chronic myelocytic leukemia, chronic myeloid leukemia, or chronic granulocytic leukemia.
What Happens in CML?
New blood cells are made in the bone marrow and can develop into one of three kinds:
- Red blood cells that carry oxygen and other necessary nutrients through the body,
- Platelets that cause blood clots to form and prevent excessive bleeding; and
- White blood cells that fight infection and disease. 4
There are several different types of white blood cells. In CML, too many white blood cells called granulocytes are made. These cells, also called leukemic cells, are not normal and will not become healthy white blood cells. They build up over time in the blood and bone marrow, crowding out the other healthy and necessary types of blood cells. When the levels of the other blood cells drop, there is much greater risk for infection, easy or excessive bleeding and anemia. 5
Why Does CML Occur?
Most people with CML have an abnormality called the Philadelphia chromosome 6. Chromosomes are organized structures of DNA (the basic genetic material of all living things) that are found in the nucleus (centre) of cells and determine how they look and act by carrying genetic information in the form of genes. 7
The Philadelphia chromosome results from pieces of two different chromosomes 8 breaking off and joining together to create an abnormal chromosome. This change causes the bone marrow to make too many granulocytes or abnormal white blood cells. 9
The Philadelphia chromosome is named for the city where it was discovered in 1960. It develops in patients after birth, so it is not passed on from a parent to a child. 10
- 1 MedlinePlus. Merriam-Webster. http://www.merriam-webster.com/medlineplus/acute (last accessed March 1, 2011)
- 2 MedlinePlus. Merriam-Webster. http://www.merriam-webster.com/medlineplus/myelogenous (last accessed March 1, 2011)
- 3 MedlinePlus. Merriam-Webster. http://www.merriam-webster.com/medlineplus/leukemia (last accessed March 1, 2011)
- 4 National Cancer Institute. U.S. National Institutes of Health. General Information about Chronic Myelogenous Leukemia. http://www.cancer.gov/cancertopics/pdq/treatment/CML/Patient (last accessed March 1, 2011)
- 5 National Cancer Institute. U.S. National Institutes of Health. General Information about Chronic Myelogenous Leukemia. http://www.cancer.gov/cancertopics/pdq/treatment/CML/Patient (last accessed March 1, 2011)
- 6 National Cancer Institute. U.S. National Institutes of Health. General Information about Chronic Myelogenous Leukemia. http://www.cancer.gov/cancertopics/pdq/treatment/CML/Patient (last accessed March 1, 2011)
- 7 Oxford Dictionaries Online. http://oxforddictionaries.com/definition/chromosome (last accessed March 1, 2011)
- 8 GOLDMAN, John M. and George Q. Daley. Chronic Myeloid Leukemia – A brief history. http://www.springerlink.com/content/qg2866x773141r22/abstract/?target=print (last accessed March 1, 2011)
- 9 National Cancer Institute. U.S. National Institutes of Health. General Information about Chronic Myelogenous Leukemia. http://www.cancer.gov/cancertopics/pdq/treatment/CML/Patient (last accessed March 1, 2011)
- 10 National Cancer Institute. U.S. National Institutes of Health. General Information about Chronic Myelogenous Leukemia. http://www.cancer.gov/cancertopics/pdq/treatment/CML/Patient (last accessed March 1, 2011)
