Chronic Myelogenous Leukemia

National Organization for Rare Disorders, Inc.

Skip to the navigation


It is possible that the main title of the report Chronic Myelogenous Leukemia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • CGL
  • GML
  • chronic granulocytic leukemia
  • chronic myelocytic leukemia
  • chronic myeloid leukemia

Disorder Subdivisions

  • None

General Discussion


Chronic myelogenous leukemia (CML) accounts of about 20% of all leukemias affecting adults. It typically affects middle-aged individuals and rarely adolescents or children. CML is a slowly progressing blood and bone marrow disorder, characterized by the excessive development of white blood cells in the spongy tissue found inside large bones of the body (bone marrow), spleen, liver and blood. As the disease progresses, the leukemic (blast) cells invade other areas of the body including the intestinal tract, kidneys, lungs, gonads and lymph nodes. These diseased cells do not grow old and eventually die like normal cells. They build up in huge numbers, overwhelm healthy blood cells and damage the bone marrow.

Since CML progresses slowly, many people are first diagnosed during routine blood exams before they even show symptoms. There is no cure for CML because it is not possible to eliminate all of the diseased cells in the body, however, there are many approved treatments that can achieve a long-term remission. Patients respond best to treatment when CML is in its earliest stage, so it is important to diagnose the disease as early as possible. Possible symptoms that may indicate CML are fever, night sweats, fatigue, pain below the ribs on the left side, and inexplicable weight loss. If an individual is experiencing any of the above symptoms or other signs, it is important they make an appointment with their doctor to be tested for CML.


There are three phases of chronic myelogenous leukemia. The first phase, or the chronic phase, is characterized by a slow, progressive overproduction of white blood cells. In chronic CML, fewer than 10% of the cells in the blood and bone marrow are blast (leukemic) cells. Patients in this phase have the best response to treatment. The next phase is transitional, and is called the accelerated phase, which occurs when 10%-19% of the cells are blast cells. The most advanced phase is the blastic phase. At this point, over 20% of the blood cells are blast cells). In the blastic phase, the leukemia is very aggressive and does not respond well to therapy. Approximately 85% of all individuals with chronic myelogenous leukemia enter this phase.


Many individuals with CML show nonspecific symptoms at the time of diagnosis. The most common symptoms are fatigue, weakness, itchiness, night sweats, abdominal discomfort, and weight loss. An abnormally enlarged spleen (splenomegaly) is usually discovered upon physical examination. CML is commonly diagnosed when an affected individual is undergoing blood tests for a different reason. Sometimes, no symptoms are present at all.

When the accelerated or blastic phase of CML occurs, an affected individual may experience severe weight loss, high fever, bone pain, enlargement of the liver and spleen, pain in the joints (arthralgia), , and hemorrhages appearing as patches of purplish discoloration on the skin and mucous membranes.


The exact cause of CML is not known. Blood samples of patients with CML show the presence of abnormal cells that reproduce more rapidly than normal cells. Ninety percent of these neoplastic cells show a consistent rearrangement of chromosomes. This rearrangement is the result of a transfer of genetic material from chromosome 22 to chromosome 9 and vice versa. As a result of this transference, chromosome 22 ends up shorter than normal. This shortened chromosome is known as the Philadelphia chromosome, and is present in the blood cells of 90% of people with CML. Formation of the Philadelphia chromosome results in a fused gene, called BCR-ABL. This gene contains instructions that make the disease blood cells produce far too much of a protein called tyrosine kinase. This protein causes the cancer by allowing the diseased blood cells to grow out of control.

Family history is not a risk factor for CML. The chromosome rearrangement resulting in the Philadelphia chromosome is believed to be acquired, meaning it develops after birth.

It is believed that in some cases, excessive exposure to radiation increases an individual's chances of developing the disease.

Affected Populations

CML is slightly more prevalent in males than in females. It may occur at any age, but predominately affects people in their 40s and 50s. There are more than 4,000 new cases of the 30,000 new cases of leukemia, diagnosed each year. There is an increased incidence rate of CML among people who have been exposed to radiation, such as the survivors of the atomic bombs dropped in Nagasaki and Hiroshima.

Although very rare in young patients, ages 20-29, CML may present itself in a more aggressive form, such as the accelerated phase or the blastic phase.

Standard Therapies


A diagnosis of CML is made based upon a thorough clinical evaluation, a detailed patient history and a variety of tests including blood tests, bone marrow examination, and chromosome analysis.

Routine blood tests may reveal abnormally high levels of white blood cells along with high numbers of immature white blood cells. If this is the case, a complete blood count (CBC) will be conducted. This test can provide a more detailed account of the abnormalities in the blood cells.

A sample of tissue taken from the bone marrow is needed to confirm a diagnosis. In individuals with advanced stage CML, the bone marrow has very little fat and numerous leukemic cells.

A fluorescence in situ hybridization (FISH) analysis and a polymerase chain reaction (PCR) test can identify the Philadelphia chromosome or the fused BCR-ABL gene that results from the chromosome translocation.

Clinical Testing and Work-Up

When treating CML, it is crucial to know what stage of the disease the individual is in. To determine staging, the following tests and procedures may be used:

Cytogenetic analysis: A test in which cells in a sample of blood or bone marrow are viewed under a microscope to look for certain changes in the chromosomes, such as the Philadelphia chromosome.

Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a needing into the hipbone or breastbone. They are then screened by a pathologist for abnormal cells under a microscope.

The European LeukemiaNet guidelines for 2010 specify the recommended monitoring and management of CML:


Tyrosine kinase inhibitors (TKIs) are the frontline therapy for CML.

In 2002, the FDA announced the approval of imatinib mesylate (Gleevec), as a therapeutic agent for CML.

Gleevec uses a technique known as molecular targeting to block the action of the protein tyrosine kinase, thought to be responsible for most cases of CML. Because it targets the specific cause of the disease, the treatment does not alter healthy tissues, and is thought to be easier on patients than other forms of treatment, such as interferon injections, chemotherapy, and bone marrow transplant.

For more information on Gleevec, please contact:

Novartis Pharmaceuticals Corporation

One Health Plaza

East Hanover, NJ 07936-1080

Phone: 1-888-669-6682

Other drugs that have recently been approved by the FDA are dasatinib (Sprycel) and nilotinib (Tasigna). They work in ways similar to Gleevec, by blocking tyrosine kinase.

In June of 2010, Tasigna was approved by the FDA to treat CML upon initial diagnosis. For more information about Tasigna, please contact:

Novartis Pharmaceuticals Corporation

One Health Plaza

East Hanover, NJ 07936-1080

Phone: 1-888-669-6682

Sprycel was approved in October of 2010 by the FDA to treat CML when other drugs, such as Gleevec, have been ineffective. For more information about Sprycel, please contact:

Bristol Myers Squibb

Corporate Headquarters

345 Park Avenue

New York, New York, 10154

Phone: 800-332-2056

Bosulif (bosutinib) by Pfizer was approved by the FDA in 2012 as a treatment for patients with chronic, accelerated or blast phase Philadelphia chromosome positive CML who are resistant to or who cannot tolerate other therapies. Bosulif works by blocking the signal of the tyrosine kinase that promotes the development of abnormal and unhealthy granulocytes. For more information, please go to or call 877-744-5675.

Synribo (omacetaxine mepesuccinate) by Teva Pharmaceuticals was approved by the FDA in 2012 under its accelerated approval program to treat adults with CML. This is a new treatment option for patients who are resistant to or cannot tolerate other FDA-approved drugs for chronic or accelerated phases of CML. Synribo blocks certain proteins that promote the development of cancerous cells. For more information, please go to or call 888-838-2872.

The following therapies have been used previously to treat CML:

The orphan drug Idarubicin HCI for injection (Idamycin) was approved by the Food and Drug Administration (FDA) in 1990 for the treatment of CML.

Interferon alfa-2a (Roferon A), administered by injection, received FDA approval for the treatment of CML in 1995.

Drugs that inhibit bone marrow activity (myelosuppressive drugs) may slow the progression of the disease. Hydroxyurea, a medication used to treat CML patients, may lower the white cell count and therefore reduce symptoms.

Radiation therapy of the spleen is another treatment option employed in only relatively few uncontrolled cases, either alone or in combination with chemotherapy, to slow the progression of the disease.

Bone marrow transplant, when performed during the early phase of the disease, can lead to remission and cure of this disease. However, this mode of treatment is not appropriate for all patients and does present some risks. The likelihood of success appears greatest among younger patients who are treated in the early stages of the disease.

Investigational Therapies

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.

For information about clinical trials being conducted at the National Institutes of Health (NIH) Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

TTY: (866) 411-1010


For information about clinical trials sponsored by private sources, contact:

The National CML Society provides current information about emerging drug therapies for CML:



Beers MH, Berkow R., eds. The Merck Manual, 17th ed. Whitehouse Station, NJ: Merck Research Laboratories; 1999:951-53.

Berkow R., ed. The Merck Manual-Home Edition. Whitehouse Station, NJ: Merck Research Laboratories; 1997:767-68.

Bennett JC, Plum F., eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, PA: W.B. Saunders Co; 1996:925-29.

Thoene JG., ed. Physicians' Guide to Rare Diseases. Montvale, NJ: Dowden Publishing Company Inc; 1995:481-82.


Kantarjian HM, Cortes J. New strategies in chronic myeloid leukemia. Int J Hematol. 2006;83:289-93.

Murgo AJ. Clinical trials of arsenic trioxide in hematologic and solid tumors: overview of the national cancer institute cooperative research and development studies. Oncologist. 2001; 6:22-28.

Druker BJ, et al., Lessons learned from the development of an abl tyrosine kinase inhibitor for chronic myelogenous leukemia. J Clin Invest. 2000;105:3-7.

Kantarjian HM, et al., Significance of FHIT expression in chronic myelogenous leukemia. Clin Cancer Res. 1999;5:4059-64.

Moracova J, et al., Polymerase chain reaction analyses should be used as a basis for clinical decision making in patients with chronic myelogenous leukemia. Blood. 1999;94:3609-11.

Sacci S, et al., Unexpected high incidence of severe toxicities associated with alpha-interferon, low dose cytosine arabinoside and all-trans retinoic acid in patients with chronic myelogenous leukemia. Leuk Lymphoma. 1999;35:483-89.

Reiter E, et al., Long-term follow-up of patients after related- and unrelated-donor bone marrow transplantation for chronic myelogenous leukemia. Ann Hematol. 1999;78:507-13.

Sacci S, et al., Chronic myelogenous leukemia in nonlymphoid blastic phase: analysis of the results of first salvage therapy with three different treatment approaches for 162 patients. Cancer. 1999;86:2632-41.

Hehlmann R., A chance of a cure for every patient with chronic myeloid leukemia. N Engl J Med. 1998;338:980


Mayo Clinic Staff. Chronic myelogenous leukemia. Updated October 30, 2010. Accessed March 5, 2012.

Emmanuel C Besa. Medscape. Chronic myelogenous leukemia. Updated December 14, 2011. Accessed March 5, 2012.

National Cancer Institute. Chronic Myelogenous Leukemia Treatment. Updated February 17, 2012.. Accessed March 5, 2012.


Leukemia & Lymphoma Society

1311 Mamaroneck Avenue

Suite 310

White Plains, NY 10605

Tel: (914)949-5213

Fax: (914)949-6691

Tel: (800)955-4572



American Cancer Society, Inc.

250 Williams NW St

Ste 6000

Atlanta, GA 30303


Tel: (404)320-3333

Tel: (800)227-2345

TDD: (866)228-4327


National Cancer Institute

6116 Executive Blvd Suite 300

Bethesda, MD 20892-8322


Tel: (301)435-3848

Tel: (800)422-6237

TDD: (800)332-8615



Center for International Blood and Marrow Transplant Research

Froedtert and the Medical College of Wisconsin Clinical Cancer Center

9200 W. Wisconsin Avenue

Milwaukee, WI 53226

Tel: (414)805-0700

Fax: (414)805-0714



OncoLink: The University of Pennsylvania Cancer Center Resource

3400 Spruce Street

2 Donner

Philadelphia, PA 19104-4283


Tel: (215)349-8895

Fax: (215)349-5445



Children's Leukemia Research Association

585 Stewart Avenue, Suite 18

Garden City, NY 11530

Tel: (516)222-1944

Fax: (516)222-0457



Cancer Research UK

Angel Building

407 St John Street

London, EC1V 4AD

United Kingdom

Tel: 020 7242 0200

Fax: 02071216700



Rare Cancer Alliance

1649 North Pacana Way

Green Valley, AZ 85614



Genetic and Rare Diseases (GARD) Information Center

PO Box 8126

Gaithersburg, MD 20898-8126

Tel: (301)251-4925

Fax: (301)251-4911

Tel: (888)205-2311

TDD: (888)205-3223


CMPD Education Foundation

P.O. Box 4758

Scottsdale, AZ 85261



Friends of Cancer Research

1800 M Street NW

Suite 1050 South

Washington, DC 22202

Tel: (202)944-6700



Cancer Support Community

1050 17th St NW Suite 500

Washington, DC 20036

Tel: (202)659-9709

Fax: (202)974-7999

Tel: (888)793-9355


Livestrong Foundation

2201 E. Sixth Street

Austin, TX 78702

Tel: (512)236-8820

Fax: (512)236-8482

Tel: (877)236-8820



Myeloproliferative Disease Support and Daily Email Digest

2011 Flagler Ave.

Key West, FL 33040


Tel: (305)295-4444



MPN Education Foundation

P O Box 4758

Scottsdale, AZ 85261

Tel: (480)443-1975

Fax: (480)443-1154



For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see