Chronic Myeloid Leukemia
Biology:
Chronic myeloid leukemia is a disease in which the bone marrow makes too many white blood cells. It is a slowly progressing blood and bone marrow disease that usually occurs during or after middle age, and rarely occurs in children. Blood stem cells in a CML patient end up forming many abnormal white blood cells (leukemia cells). The leukemia cells can build up in the blood and bone marrow so there is less room for healthy white blood cells, red blood cells, and platelets. When this happens, infection, anemia, or easy bleeding may occur. About 90% of CML patients have the Philadelphia Chromosome. This is a chromosomal defect caused by parts of chromosomes 9 and 22 switching places, forcing the Bcr and Abl genes together. After this the body makes Bcr-Abl which is the protein that interrupts normal blood cell processing and makes leukemia cells. The Philadelphia chromosome is not passed from parent to child. To learn more about these processes visit the biological pathways page here.
Stages:
Chronic myelogenous leukemia has 3 phases. As the amount of blast (leukemia) cells increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. The number of blast cells in the blood and bone marrow and the severity of signs or symptoms determine the phase of the disease. In chronic phase, fewer than 10% of the cells in the blood and bone marrow are blast cells. In accelerated phase, 10% to 19% of the cells in the blood and bone marrow are blast cells. In blastic phase, 20% or more of the cells in the blood or bone marrow are blast cells. When tiredness, fever, and an enlarged spleen occur during the blastic phase, it is called blast crisis. The information from tests and procedures done to detect and diagnose CML is also used to plan treatment.
Symptoms:
These and other signs and symptoms may be caused by CML or by other conditions. Check with your doctor if you have any of the following:
- Feeling very tired.
- Weight loss for no known reason.
- Night sweats.
- Fever.
- Pain or a feeling of fullness below the ribs on the left side.
Statistics:
The American Cancer Society's estimates for CML in the United States for 2014 are:
The average age at diagnosis of CML is around 64 years. Almost half of cases are diagnosed in people 65 and older.
- About 5,980 new cases will be diagnosed with CML (3,130 in men and 2,850 in women).
- About 810 people will die of CML (550 men and 260 women).
The average age at diagnosis of CML is around 64 years. Almost half of cases are diagnosed in people 65 and older.