Blast crisis is the third phase of chronic myeloid leukemia (CML) and the most difficult to treat. New types of targeted therapy have improved the treatment and outlook for people in all phases of CML.
Chronic myeloid leukemia (CML) is a type of blood cancer that makes up about
- certain types of white blood cells
- red blood cells
CML causes your body to produce too many abnormal and immature blood cells called blasts. These abnormal cells can crowd out the production of healthy blood cells.
Doctors don’t stage CML like most types of cancer but instead divide it into three phases depending on how many abnormal cells your body produces:
- the chronic phase
- the accelerated phase
- blast crisis
Blast crisis is the third phase of CML and the most difficult to treat. Recent advances in a type of targeted therapy called tyrosine inhibitors have greatly improved the outlook for people with CML in general and moderately improved the outlook for people in blast crisis.
Read on to learn more about blast crisis in CML, including how it’s defined, its symptoms, and how it’s treated.
Blast crisis is the third phase of CML.
CML tends to develop slowly. It isn’t staged like most types of cancer. Doctors divide it into
People in the chronic phase have less than
The accelerated phase usually lasts about 3 to 9 months.
People are in the accelerated phase if they have more than
- poor appetite
- weight loss
Blast crisis is the third phase and the hardest to treat. In this phase, the cancer starts to act like a more aggressive type of leukemia called acute myeloid leukemia (AML). About
You’re considered to be in the blast crisis if your blood and bone marrow samples contain more than 20% or 30% blasts, depending on which classification system is used. The
Symptoms are generally more severe than in previous phases, and leukemia may spread to
- lymph nodes
- nervous system
AML and CML in blast crisis
AML is a more aggressive type of leukemia. CML in blast crisis can act like AML, but identifying which leukemia you have is important for deciding on the best treatment options.
Doctors can differentiate them by identifying a certain genetic mutation called the Philadelphia chromosome that’s present in almost all people with CML but is rare among people with AML.
Blast crisis can cause symptoms such as:
- anemia, which can cause
- frequent infections
- tenderness in your abdomen
- shortness of breath
- abdominal pain
- abnormal bleeding or bruising
- poor appetite
- unintentional weight loss
- bone pain
Blood and other tests may reveal signs such as:
- high white blood cell count
- very high or low platelet count
- blast cells that have spread to other organs
- new chromosome abnormalities in cancerous cells
When deciding how to treat CML in a blast crisis, doctors consider
- whether your cancer has returned after treatment
- whether you have elevated levels of abnormal myeloid cells or abnormal myeloid and lymphoid cells
- which tyrosine kinase inhibitors you’ve been exposed to
- whether you have a BCR-ABL1 gene mutation
- whether you’re a candidate for intensive chemotherapy and a stem cell transplant
According to the
- targeted therapy with a tyrosine kinase inhibitor
- high doses of chemotherapy
- stem cell transplant
- chemotherapy to relieve symptoms or improve quality of life
- a clinical trial of a new treatment
Tyrosine kinase inhibitors improving treatment and outlook
The development of tyrosine kinase inhibitors has revolutionized treatment over the last
Tyrosine kinase inhibitors you may receive include:
The overall 5-year survival rate for CML has risen from
People in the blast crisis phase of CML have a poorer outlook than people in earlier phases. In a
Researchers are continuing to investigate how to best treat advanced CML, and it’s likely that the survival rate will continue to increase in the future.
Blast crisis is the final phase of CML. A doctor may diagnose blast crisis if you have more than 20% or 30% abnormal cells in your bone marrow and blood samples.
A type of targeted therapy called has drastically improved the outlook for people with CML. Tyrosine kinase inhibitors are often administered alone or combined with other treatments such as chemotherapy.