What is chronic myeloid leukemia?
Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, is a fairly slow growing cancer that starts in the bone marrow. It’s a type of leukemia that affects the myeloid cells -- cells that form blood cells, such as red blood cells, platelets, and many types of white blood cells.
In CML, leukemia cells tend to build up in the body over time. In many cases, people don't have any symptoms for at least a few years. CML can also change into a fast-growing, acute leukemia that invades almost any organ in the body. Most cases of CML occur in adults, but it is also very rarely found in children. As a rule, their treatment is the same as for adults.
What is leukemia?
Leukemia is a type of cancer that starts in cells that form new blood cells. These cells are found in the soft, inner part of the bones called the bone marrow.
Any blood-forming cell can turn into a leukemia cell. Once that happens, the cell can grow and divide to form many new cancer cells. These cells can take over the bone marrow, spill out into the bloodstream, and spread to other organs. The buildup of these cells can lead to a shortage of normal blood cells. Having too many leukemia cells can keep other cells in the body from working the way they should.
Leukemia is different from other types of cancer that start in organs such as the lungs, colon, or breast and then spread to the bone marrow. Cancers that start elsewhere and then spread to the bone marrow are not leukemia.
CML isn’t the only kind of leukemia. There are 4 main types of leukemia:
- Acute lymphocytic leukemia
- Acute myeloid leukemia
- Chronic lymphocytic leukemia
- Chronic myeloid leukemia
Knowing the exact type can help doctors better predict each patient's outlook (prognosis) and select the best treatment.
The rest of this information is about chronic myeloid leukemia (CML) in adults only.
Last Medical Review: 02/03/2015
Last Revised: 02/03/2015