Leukemia Chronic Myelogenous Treatment

Chronic myelogenous leukemia (CML) is a cancer of the bone marrow. In its initial stages, CML develops slowly, but the disease accelerates rapidly in its final phase. CML occurs because of a chromosomal translocation where part of chromosome 9 switches places with chromosome 22. This translocation results in the Philadelphia chromosome, triggering excessive production of abnormal white blood cells.

Chronic myelogenous leukemia treatment may include imatinib therapy, interferon therapy, a bone marrow transplant or cord blood transplantation.

Stages of Chronic Myelogenous Leukemia

Chronic myelogenous leukemia has three phases, and treatment depends on the disease’s stage at the time of diagnosis:

  • Chronic CML: White blood cell levels build up slowly for two to five years, often without noticeable symptoms.
  • Accelerated CML: Immature white blood cells called blasts accumulate in the blood, bone marrow, spleen and liver. Weight loss, anemia, night sweats, fever and other symptoms become more common.
  • Blast phase/blast crisis: Immature blast cells accumulate rapidly, crowding out healthy blood cells. During this phase, CML resembles acute types of leukemia.

Most cases of chronic myelogenous leukemia are diagnosed during the chronic phase. Treatment of CML becomes less effective as the disease progresses.

Imatinib Therapy

Imatinib therapy is the initial treatment for most cases of CML. Imatinib is a targeted therapy known as a “kinase inhibitor.” Kinase inhibitors block the action of a protein called “tyrosine kinase.” By blocking tyrosine kinase, imatinib therapy prevents leukemia cells from replicating and multiplying.

Imatinib therapy is a relatively new treatment, so its long-term success and effects have yet to be fully determined. However, a study published in the New England Journal of Medicine (2006) found that the five-year survival rate for people treated with imatinib as an initial therapy was 95 percent. Because imatinib therapy doesn’t cure chronic myelogenous leukemia, ongoing treatment is needed.

Patients who don’t respond to imatinib therapy may receive other targeted medications, including dastinib and nilotinib. These targeted therapies work best in cases of CML diagnosed in the chronic phase.

Stem Cell Transplants

Imatinib therapy may not for every case of CML, particularly once the disease enters the accelerated or blast phases. In such cases, a stem cell transplant may be suggested. A bone marrow transplant or umbilical cord blood transplantation, if successful, can cure chronic myelogenous leukemia. In contrast, imatinib therapy only keeps the disease in check.

A bone marrow transplant or cord blood transplantation is, however, a complex procedure with potentially serious complications. As a result, this approach tends to be reserved for patients who don’t respond to other treatments.

Interferon Therapy and Chronic Myelogenous Leukemia

Interferon therapy uses a synthetic form of an immune system cell to combat CML. Interferon therapy strengthens the body’s immune system, with the goal of stimulating it to attack cancer cells and reduce the growth of leukemia cells.

While interferon therapy was once a common CML treatment, it isn’t as frequently used now. However, interferon therapy may be an option if other treatments fail or can’t be used (such as during pregnancy).

Resources

American Cancer Society. (2010). Leukemia: Chronic myeloid (myelogenous) detailed guide. Retrieved September 29, 2010, from http://www.cancer.org/Cancer/Leukemia-ChronicMyeloidCML/DetailedGuide/index.

Druker, B., Guilhot, F., O’Brien, S., Gathmann, I., Kantarjian, H, … Larson, R. (2006). Five-year follow-up of patients receiving imatinib for chronic myeloid leukemia. Retrieved September 28, 2010, from http://www.nejm.org/doi/full/10.1056/NEJMoa062867 – t=articleDiscussion.

Mayo Clinic. (2008). Chronic myelogenous leukemia. Retrieved September 29, 2010, from http://www.mayoclinic.com/health/chronic-myelogenous-leukemia/DS00564/DSECTION=treatments-and-drugs.

National Cancer Institute. (2009). Chronic myelogenous leukemia treatment (PDQ): Treatment option overview. Retrieved September 29, 2010, from http://www.cancer.gov/cancertopics/pdq/treatment/CML/Patient/page4.

National Marrow Donor Program. (n.d.). Chronic myelogenous leukemia (CML), imatinib (gleevec) and transplant. Retrieved September 29, 2010, from http://www.marrow.org/PATIENT/Undrstnd_Disease_Treat/Lrn_about_Disease/CML/index.html.