Massachusetts General Hospital

Chronic Myelogenous Leukemia

What is chronic myelogenous leukemia?

Chronic myelogenous leukemia (CML) is a cancer of the blood in which too many granulocytes, a type of white blood cell, build up in the bone marrow.

Normally, bone marrow cells mature into several different types of blood cells. CML affects the young blood cells called blasts that normally develop into a type of white blood cell called granulocytes. The main function of granulocytes is to destroy bacteria. The blasts do not mature, increase to large numbers, and remain in the bone marrow and blood.

Chronic myelogenous leukemia can occur over a period of months or years. A specific chromosome rearrangement is found in the cells of almost all patients with CML. Part of chromosome #9 breaks off and attaches itself to chromosome #22, so that there is an exchange of genetic material between these two chromosomes. This rearrangement changes the position and functions of certain genes, which results in uncontrolled cell growth. Other chromosome abnormalities can also be present.

CML occurs mainly in adults and is rare in children. According to the American Cancer Society, about 47,000 leukemia cases are expected in the United States in 2012. CML will account for about 5,400 of these cases.

What are the symptoms of chronic myelogenous leukemia?

Many people do not have symptoms in the early phase of CML. Instead, the leukemia is found during routine blood tests. When people do have symptoms from CML, the following are the most common. However, each individual may experience symptoms differently. Symptoms may include:

• Night sweats

• Weight loss

• Fever

• Persistent weakness

• Fatigue

• Aches in bones and joints

• Enlarged spleen

The symptoms of chronic myelogenous leukemia may resemble other blood disorders or medical problems. Always consult your doctor for a diagnosis.

How is chronic myelogenous leukemia diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for chronic myelogenous leukemia may include:

• Blood tests and other evaluation procedures

• Bone marrow aspiration and/or biopsy. A procedure that involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size, and maturity of blood cells and/or abnormal cells.

Treatment for chronic myelogenous leukemia

Specific treatment for chronic myelogenous leukemia will be determined by your doctor based on:

• Your age, overall health, and medical history

• Extent of the disease

• Your tolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

Treatment may include:

• Targeted therapies, such as Gleevec (imatinib), Sprycel (dasatinib), or Tasigna (nilotinib)

• Chemotherapy

• Biological therapy. This therapy uses the body's immune system to fight cancer.

• Radiation therapy

• Stem cell transplantation

• Splenectomy. Surgery to remove the spleen.