Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a blood cancer. It begins in myeloid cells which are made in the spongy center of bones (bone marrow). It is a long-term (chronic) cancer. This means that people often live with it for many years, either when it’s not active (in remission) or when it’s being controlled with treatment. 

Healthy myeloid cells form a balance of different blood cells: red cells, some types of white cells, and platelets. In CML, genetic changes cause myeloid cells to produce blood cells that grow out of control. This leads to an increase in white blood cells, abnormal numbers of platelets, and low numbers of red blood cells. When red blood cells are at low levels, they have a hard time carrying enough oxygen through the body. This can cause symptoms like tiredness or shortness of breath. 

Risk Factors

A small percent of all leukemia cases are CML. The exact cause of CML is not fully understood, but researchers are continuing to learn more. It is known that a genetic mutation (known as the BCR-ABL gene) leads to CML. Radiation exposure and older age are two known risk factors associated with CML.

The genetic change that causes CML is not the type that gets passed down from parents to children. It happens spontaneously within only certain cells in a person’s body during their lifetime.

CML symptoms often start as mild, unclear problems that can be easy to miss. Some people may have no symptoms at all. If there are symptoms, they can include:

• Feeling tired or weak
• Losing weight
• Fevers
• Sweating (especially at night)
• Pain or fullness in the left side of the belly. This may happen when the spleen — an organ that filters your blood and helps fight infection — gets bigger than normal.
• Bone pain

These symptoms could be linked to other conditions or causes that are more common than CML. For this reason, many people are surprised to be diagnosed with this blood cancer.

Talk to your doctor about any signs or symptoms you are experiencing. If you have concerns or feel you are not getting the care you need, you can always seek a second opinion. 
 

Diagnosing CML

If you experience symptoms or have results of a blood test that may indicate CML, there are several tests that your care team may perform to diagnose CML. They include:

Medical history and physical exam: Check your overall health. Check for signs like swollen spleen, liver, or lymph nodes, belly pain, or signs of bleeding.

Blood tests: Check the complete blood count (also called “CBC”). Measures the levels of different cells in your blood, including different types of white blood cells.

Bone marrow tests (called aspiration and biopsy)​: Removes a small amount of bone marrow from the pelvic bone (hip), or less commonly, the breastbone (sternum). The sample is looked at closely to see the blood-forming cells. The number of immature white blood cells (blasts) is used to tell the phase of CML.

Gene and chromosome testing: Looks at the bone marrow and blood to confirm a CML diagnosis and learn more about CML cells. Three types:

• Cytogenetics (also called karyotyping) – Looks at whole chromosomes (pieces of DNA) to check their structure and function
• Fluorescence in situ hybridization (FISH) – A type of cytogenetics that uses fluorescent (glowing) tags to “light up” specific sections of DNA
• Quantitative polymerase chain reaction (qPCR) – A type of cytogenetics that measures the amount of BCR-ABL gene

After receiving a CML diagnosis, ask to be referred to a CML specialist. They are highly trained to understand and treat CML. They may also connect you with clinical trials.

Phases and Risk Scores of CML

Tests that diagnose CML also show the phase of the disease. The number of immature white blood cells (blasts) in the blood or bone marrow helps determine the phase of CML. Overall, the phase describes how much CML has grown and if it is aggressive. Different phases require different treatment.

The 3 phases of CML are:

• Chronic phase − Most patients are diagnosed during the chronic phase. CML in this phase often responds well to treatment. This phase has the least number of blasts in the blood or bone marrow. 
• Accelerated phase − Means that the number of blasts is higher, the spleen is large, and blood counts are out of balance. For example, platelets may drop low. This phase is harder to treat. There are more changes in the genes of the leukemia cells. 
• Blast or blast crisis phase − Means that the number of blasts increases to the point where it looks and behaves like acute myeloid leukemia or acute lymphoid leukemia. CML in the blast phase is more difficult to treat. Treatment may bring it back to the chronic phase or into remission. However, more aggressive treatments are often still needed to keep CML in remission, including a stem cell transplant.  

Without treatment, the chronic phase of CML can progress to the accelerated or blast phases within a few years. With certain treatment, such as targeted therapy, the progress to these higher phases is greatly reduced. See the next section for more information about the treatments for CML. 

Because CML is a chronic condition, most people need treatment for a long time. It helps to learn as much as you can about treatment before you begin, including any side effects. Side effects from treatment may impact your quality of life. At all times during treatment, be sure to tell your care team how you feel. There are many ways your care team can help you manage symptoms and side effects.

Be sure to speak with your care team about your goals and preferences for treatment. You and your loved ones are important members of the care team. Having this shared decision-making for your care is important to ensure that you are receiving the care you want.

Monitoring CML Treatment

Many of the same tests used to diagnose CML are used to see how the treatment is working. Below is a list of tests that your care team may use:

• Polymerase chain reaction (PCR) – This is the gold standard test for measuring response to CML treatment. It tells your doctors how much BCR-ABL gene remains in your body. Remission is measured as early molecular response (EMR), major molecular response (MMR), or deep molecular response (DMR).
• Cytogenetics or FISH – Measures the percentage of bone marrow cells that show the Philadelphia chromosome. Your team will look for major cytogenic response (MCyR) or complete cytogenetic response (CCyR).
• Complete blood count (CBC) with differential – To see if blood cell counts have returned to normal levels. This is called complete hematologic response (CHR).

You will likely need to manage CML treatment and its side effects for the rest of your life. Learning to live with a chronic condition, such as CML, can be difficult and cause feelings of distress or overwhelm. There are things you can do to live well and feel in control.

Tips for coping with CML:

• Take care of your body. Focus on nutrition and exercise based on your care team’s guidance. If you smoke, try to stop.
   
• Increase energy levels by staying active throughout the day. Maintain a consistent sleep schedule.
   
• If you feel sad or depressed, let your care team know. They can refer you to a licensed mental health professional or recommend available support groups.  
   
• Once your treatment is stable, you might only see your doctor a few times per year. If you change anything (stop or start something new), let someone on your care team know. Even small changes can affect how well the drugs work.
   
• Connect with others with CML who may better understand your experiences. They can offer support and share resources that have helped them. Local resources, like those at CSC’s and Gilda’s Clubs, may have a blood cancer support group.
   
• If you can’t find a local resource for personal CML support, consider trusted information online. Seek webpages and other online resources offered by blood cancer-specific patient groups, such as Blood Cancer United. Cancer Support Community’s MyLifeLine connects cancer patients and caregivers with friends and family to reduce stress, anxiety, and isolation. By creating your own private website, our goal is to help you find hope, regain control, document your journey, and receive social, emotional, and practical support from friends and family throughout the treatment process and beyond. 
   
• Ask the hospital’s social worker or your care team how to get in-home support if you need it.
   
• Consider asking friends and family to help with household tasks, cooking, cleaning, errands, rides, childcare, financial support, etc. CSC’s MyLifeLine.org also offers an online planner that you may find helpful. 

Costs of Care

The treatment for CML and follow-up appointments can be costly. Many families worry about the costs of cancer care, and they don't know where to turn. If you have health insurance, it’s important to learn about what is covered. Consider talking with a financial counselor or call our Cancer Support Helpline CSC-867-5309 (272-867-5309) and ask to speak with the financial navigator.

Support for Caregivers

The ripples of a CML diagnosis extend to spouses, partners, siblings, children, and friends. They may experience their own challenges with providing care and navigating the realities of their loves one’s CML. Many family members may need to become caregivers for the first time. It is important for caregivers to also seek and receive the support they need.