Chronic myeloid leukemia (CML)

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What is chronic myeloid leukemia (CML)?

Chronic myeloid leukemia (CML) is a slow-developing cancer of the bone marrow in which immature cells called “blasts” overtake the healthy bone marrow. Patients with CML have an abnormal chromosome in their blood cells called the Philadelphia chromosome. No one is born with the Philadelphia chromosome; rather it is a result of a genetic accident that happens in a blood-forming stem cell in the bone marrow. It is actually a combination of 2 chromosomes (chromosomes 9 and 22) that become abnormally fused. This fusion results in the creation of a new gene called BCR-ABL.

Chronic myeloid leukemia is classified as a myeloproliferative neoplasm. These are slow growing types of leukemia which result in overproduction of white blood cells by the bone marrow, causing high blood counts.

Chronic myeloid leukemia (CML) may also be referred to as chronic myelogenous leukemia, chronic myelocytic leukemia or chronic granulocytic leukemia.

CML symptoms and signs

Signs and symptoms of CML may look like other signs and symptoms of diseases or conditions.

If you have any, some, or all, of these symptoms*, please speak with your physician:

  • Pale skin
  • Shortness of breath
  • Tiredness, lethargy
  • Night sweats
  • Unexplained weight loss / loss of appetite
  • Enlarged spleen or liver (upon physician examination)

*From the Leukemia and Lymphoma Society

How is CML diagnosed?

Many people do not have symptoms of chronic myeloid leukemia (CML) when they are diagnosed. They may be diagnosed during a routine checkup, or if their family doctor prescribes blood tests for an unrelated issue.

If your doctor suspects CML, further leukemia diagnosis tests will determine if you have the Philadelphia chromosome, or the Bcr-Abl oncogene. The phase of your CML will also be identified, usually by a bone marrow biopsy. Knowing all of this information will allow us to use different targeted therapies specific to your type of cancer.

Staging chronic myeloid leukemia

Chronic myeloid leukemia (CML) is not staged like other solid tumor cancers. Instead, CML is broken down into three phases. The number of blasts present in the blood stream identifies each phase.

  • The Chronic Phase: In the Chronic Phase, people with CML may have little or no symptoms at all. A blood test may detect the CML. In this phase, the CML may be controlled with drugs. If you become resistant to drugs, your disease may progress to the next phase, the Accelerated Phase.
  • The Accelerated Phase: In the Accelerated Phase of CML, you may begin experiencing symptoms associated with an enlarged spleen, low red blood cell count, or an increase or decrease in white blood cells.
  • The Blast Phase: The Blast Phase of CML is diagnosed when you have an increase of blast cells in your bone marrow and blood. In this phase, you are at higher risk for other complications of CML such as shortness of breath, infection and bleeding. Once CML gets to the Blast Phase, it can accelerate into acute lymphocytic leukemia (ALL) or acute myeloid leukemia (AML), and requires immediate medical attention.

CML Diagnosis at Penn Medicine

Bone Marrow Biopsy
Bone Marrow Biopsy

CML treatment process and options

The diagnosed phase of your chronic myeloid leukemia (CML) and presence of the Philadelphia chromosome, or Bcr-Abl oncogene, will determine your treatment plan. Penn Medicine's Abramson Cancer Center's hematologists and medical oncologists are part of large multidisciplinary leukemia treatment teams whose approach to cancer and blood disorders is to treat the entire individual — not just the disease. Some of the procedures used to treat your CML include the following:

CML Treatment

The diagnosed phase of your chronic myeloid leukemia (CML) and presence of the Philadelphia chromosome, or Bcr-Abl oncogene, will determine your treatment plan. Penn Medicine's Abramson Cancer Center's hematologists and medical oncologists are part of large multidisciplinary leukemia treatment teams whose approach to cancer and blood disorders is to treat the entire individual — not just the disease. Some of the procedures used to treat your CML include the following:

Stem cell (bone marrow) transplant
Penn Medicine provides bone marrow transplants to replace abnormal plasma cells with healthy cells.
Immunotherapy
This treatment boosts the immune system, enhancing its ability to recognize and eliminate abnormal cells.
Chemotherapy
This treatment uses strong medicines to target and eliminate cancer cells and to prevent their spread.
Targeted therapy
This cancer treatment uses powerful medications to help identify and disable certain types of cancer cells.
National Cancer Institute "Designated Comprehensive Cancer Center" badge on top of exterior shot of the Perelman Center for Advanced Medicine

Rated “exceptional” by The National Cancer Institute

Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.

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When you need help with a blood disorder, Penn Medicine’s Hematology team offers advanced, expert care.

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