Chronic myelogenous leukemia (CML), also known as chronic myeloid leukemia, starts in blood-forming cells of the bone marrow and invades the blood.
Although most CML cases are slow-growing, often with no symptoms, some CML cases can turn into faster-growing, acute leukemia that invades almost any organ in the body. At UC San Diego Medical Center, Dr. Catriona Jamieson has made a pioneering discovery of candidate cancer stem cells involved in the progression of CML to acute leukemia. As a result, she has devised methods to detect cancer stem cells in the body, thereby permitting a comprehensive assessment of novel cancer stem cell diagnostics and therapeutics.
Most CML patients have a chromosomal abnormality called the Philadelphia chromosome. Additionally, researchers have learned that a cancer gene is created when pieces break off chromosomes 9 and 22, with the segments joining to make a gene called BCR-ABL, that leads to CML. A small number of CML patients have the BCR-ABL gene but don’t seem to have the Philadelphia chromosome.
- Shortness of breath (which may be caused by anemia)
- Excessive bruising
- Frequent or severe nose bleeds
- Bleeding gums (due to a shortage of normal white blood cells)
- Pale skin
- Night sweats
- Bone pain
- Enlarged spleen
- Pain or a sense of fullness in the abdomen
- High levels of radiation, such as high-dose radiation therapy used to treat other cancers
Depending on the phase of CML that has been diagnosed, treatment options include:
In recent years, new drugs that target specific parts of cancer cells have become standard treatment for people with early stage CML. Among these is imatinib, which is commercially known as Gleevec. It specifically targets and inhibits the BCR-ABL protein. Almost all patients respond well to treatment with Gleevec, with most responses lasting for many years. Additional drugs that target the BCR-ABL protein include dasatinib and nilotinib.
Chemotherapy, consisting of anti-cancer drugs taken by mouth or injection, is no longer the main treatment for CML. Its main role at this time is as part of the treatment during a blood and marrow transplant (BMT). It may also be used by itself later in the course of disease if other treatments have stopped working.
Blood and Marrow Transplant (BMT)
Blood and bone marrow transplantation (BMT) is a treatment option for CLL patients. The two primary types of BMT are autologous (using your own previously harvested cells) and allogeneic (using cells from a donor). Both are preceded by high-dose chemotherapy and/or radiation, which destroy not only the cancerous cells in your body, but healthy cells as well. You will be in the hospital during this time, to ensure that you are not exposed to possible infection. Then, during the transplant procedure, you’ll receive healthy donor cells which make their way to your bone marrow and start producing new blood cells.
Radiation therapy, treatment with high-energy rays to destroy cancer cells, is not usually part of the main treatment for CML patients. If, however, you have swollen internal organs (such as an enlarged spleen), radiation therapy may be used to reduce the number of cancer cells and shrink the organ.
Splenectomy is surgical removal of the spleen, which is infrequently done and usually chosen to reduce symptoms from an enlarged spleen such as pain and extreme pressure.