What is CML?
CML is caused by an abnormally high production of white blood cells, which are cells of the immune system made in the bone marrow. These cells have an abnormal chromosome called the Philadelphia chromosome. This chromosome causes the abnormal cells to have certain activity and growth patterns that are not regulated by the normal signals, so they grow and multiply in the blood stream. Many patients find they have CML during a routine blood test during a physical examination, and they often have no symptoms at all.
What is the normal course of the disease in CML?
It's variable, but doctors do have some road marks that can help predict the course. “We look at the characteristics of the white blood cell count when the patient is first diagnosed,” says Nichols. “We also look at whether or not they have newly-formed abnormal cells in their bone marrow.” That's associated with a worsening prognosis. The last thing that doctors look at is whether or not the CML cells have gone to other organs and are increasing the size of those organs; in particular, the spleen.