Chronic Myelogenous Leukemia (CML)
Chronic myelogenous leukemia (CML) is a slowgrowing cancer of the white blood cells. It is also sometimes called chronic myeloid, chronic granulocytic or chronic myelocytic leukemia. CML is a common leukemia. In the United States, more than 20,000 people have CML and about 4,600 new cases are diagnosed each year. Most cases of CML appear in adults, but about 2 to 4% of CML patients are children.
CML patients have bone marrow that makes too many white blood cells. CML is caused by a change in the genetic code of some of the cells in the bone marrow. In these cells, part of chromosome 9 moves to chromosome 22. This creates an abnormal chromosome called the Philadelphia chromosome.
The Philadelphia chromosome makes an enzyme (called tyrosine kinase) that signals the body to make too many white blood cells. Doctors do not know what causes the Philadelphia chromosome to appear.
Phases and Symptoms
CML has three phases. Most patients are diagnosed in the first phase, called the chronic phase. It can develop over time into the second (accelerated) and third (blast) phase.
Chronic Phase
In the chronic phase, there are more white blood cells in the blood and bone marrow than usual. Most are mature cells that can work normally. Depending on treatment, the chronic phase may last two to five years or more before turning into the accelerated phase. The symptoms of chronic phase CML depend on how high the person’s white blood cell count is. Often, people do not notice any symptoms at all. Their CML is found during a routine doctor’s visit.
Accelerated Phase
In the accelerated phase, there are more blasts (immature white blood cells) in the marrow, blood, liver and spleen. The blasts cannot fight infections the way normal white blood cells do. This phase may last one to three months before reaching the blast phase. Symptoms are more noticeable than in chronic phase.
Blast Phase
In the blast phase, the number of blasts in the bloodstream grow rapidly. As a result, there are fewer normal blood cells (white blood cells, red blood cells and platelets), and the symptoms listed above become severe. Patients often have problems with bruises, bleeding and infection.
Thanks: AADP.org