Chronic Myeloid Leukemia (CML): Staging and Treatment
What is staging for cancer?
Staging is the process of learning how much cancer is in your body and where it is. While most cancers form tumors, CML does not. It is found in the blood and bone marrow but also can be found in organs of the body. Tests like blood counts, flow cytometry to look for markers on cancer cells, bone marrow biopsy, and blood tests to look at chromosomal changes are done to help stage your cancer. Your providers need to know about your cancer and your health so that they can plan the best treatment for you.
How is CML staged?
Staging for CML is broken down into three phases. The phases are identified by the number of immature white blood cells (called blasts) in the bloodstream.
- Chronic: There are less than 10% blast cells in the blood. This is the least aggressive of the phases.
- Accelerated: There are between 10-19% blast cells in the blood.
- Blast: There are 20% or more blast cells in the blood. This is the most aggressive phase of the disease.
How is CML treated?
Treatment for CML depends on the stage/phase of your disease, your overall health, and your goals. You and your care team will work together to decide the best plan for you. Some treatments used in CML include:
Targeted Therapy
Targeted therapies are medications that target a specific pathway in the growth and development of a cancer cell. The targets themselves are often a certain molecule (or small particle) in the body that is known or thought to play a role in cancer formation. The type of targeted therapy medications used in the treatment of CML are tyrosine kinase inhibitors (TKI). Kinase inhibitors block growth signals within cancer cells, slowing or stopping the growth of new cancer cells.
TKIs used in the treatment of CML include asciminib, imatinib, dasatinib, nilotinib, bosutinib, and ponatinib. These medications do not cure CML but keep the disease from progressing to acute leukemia. You will have regular blood tests to measure your response to TKI therapy.
Bone Marrow Transplant
Transplants can be done using a donor's bone marrow or stem cells (allogeneic) or your own bone marrow or stem cells (autologous). Allogeneic transplants are more commonly used in patients with CML. Giving you a donor's marrow after marrow-killing (marrow-ablating) chemotherapy serves to "rescue" you with healthy bone marrow. One effect that providers see as a very important part of all allogeneic transplants is called the "graft versus tumor effect.” This is the effect that the donor's immune system (which is part of the marrow that the donor donated) has on your cancer cells. The hope is that the healthy donor immune system can attack any stray cancer cells that survived the treatment before the transplant. Bone marrow transplants are not a first-line therapy for CML patients but may be used in patients who are no longer responding to TKI therapy.
Other Treatments
Other types of treatments may be used in cases where TKIs are no longer working to manage the disease. These include:
- Omacetaxine mepesuccinate (Synribo™) is a manmade form of homoharringtonine, a compound purified from a Chinese evergreen tree. It can be used in patients who have not responded to 2 or more TKI medications.
- Interferon alfa may be used in pregnant women and for others who cannot have a transplant.
- Chemotherapy: May be used in combination with TKI in preparation for transplant.
- Radiation: May be used to palliate (relieve) symptoms related to bone pain or an enlarged spleen. It also may be used in preparation for transplant but is not used to treat underlying CML.
- Surgery: In some people with CML, the spleen can become enlarged and press against other organs. A splenectomy (removal of the spleen) may be needed.
Clinical Trials
You may be offered a clinical trial as part of your treatment plan. To find out more about current clinical trials, visit the OncoLink Clinical Trials Matching Service.
Making Treatment Decisions
Your care team will make sure you are included in choosing your treatment plan. This can be overwhelming as you may be given a few options to choose from. You can take a few weeks to meet with different providers and think about your options and what is best for you. This is a personal decision. Friends and family can help you talk through the options and the pros and cons of each, but they cannot make the decision for you. You need to be comfortable with your decision – this will help you move on to the next steps. If you ever have any questions or concerns, be sure to call your team.
You can learn more about CML at OncoLink.org.