Your chronic myeloid leukemia phase plays a large part in determining the type of treatment you'll receive. CML has three phases:
- the chronic phase
- the accelerated phase
- the blast crisis phase
Each phase describes CML's progression, determined by the number of blast cells - white cells that don't fully form as they should, blocking production of functioning blood cells - in the blood and bone marrow.
Chronic Phase CML
Most patients are diagnosed during CML's chronic phase when symptoms are mild or not noticeable. During this phase, your white cells can still fight infection. In most cases, long-term drug therapy can control chronic phase CML, and you can usually return to normal activities after treatment begins.
A small number of people diagnosed and treated during the chronic phase progress to the accelerated phase. These patients appear to stop responding to treatment as the disease advances.
Accelerated Phase CML
If you're diagnosed during accelerated phase CML, your blood may have:
- a lower-than-normal number of red cells, which can cause anemia and fatigue
- a low number of platelets
- an increase or decrease in white cells
- a high number of blast cells
You may also have a swollen spleen, which can cause stomach discomfort, and a general feeling of ill health.
Blast Crisis Phase CML
If you're diagnosed in CML's blast crisis phase, you have an increased number of blast cells in your bone marrow and blood. You generally also have lower-than-normal numbers of red cells and platelets. In this phase you may experience:
- a lack of energy or feelings of tiredness
- shortness of breath
- stomach pain (from an enlarged spleen)
- bone pain
Once CML reaches this more severe, advanced phase, its effects on patients are similar to those caused by an acute leukemia and can be life threatening. In about 25 percent of people, the transformation in the blast crisis takes on the appearance of acute lymphoblastic leukemia, while in the majority it takes on the appearance of acute myeloid leukemia.