Cancer Institute A national cancer institute
designated cancer center

Chronic Myelogenous Leukemia

What is leukemia?
Leukemia is cancer of the blood cells, usually the white blood cells.

What are the types of leukemia?
There are four main types of leukemia, which can be further divided into subtypes. When classifying the type of leukemia, the first steps are to determine if the cancer is:

1. lymphocytic or myelogenous leukemia:
Cancer can occur in either the lymphoid or myeloid white blood cells.

›When the cancer develops in the lymphocytes (lymphoid cells), it is called lymphocytic leukemia.

› When the cancer develops in the granulocytes or monocytes (myeloid cells), it is called myelogenous leukemia.

2. acute or chronic leukemia:
Leukemia is either acute or chronic.

acute leukemia
The new or immature cells, called blasts, remain very immature and cannot perform their functions. The blasts increase in number rapidly, and the disease progresses quickly.

chronic leukemia
There are some blast cells present, but they are more mature and are able to perform some of their functions. The cells grow more slowly, and the number increases less quickly, so the disease progresses gradually.

Based on these findings, the leukemia is then classified into one of the four main types of leukemias: acute myelogenous leukemia (AML); chronic myelogenous leukemia (CML); acute lymphocytic leukemia (ALL); or chronic lymphocytic leukemia (CLL).

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, are produced 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 develop into a type of white blood cell (called granulocytes). The main function of granulocytes is to destroy bacteria. The blasts, which do not mature and become too numerous, 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 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, of the 33,440 leukemia cases expected in 2004 about 12,790 will be chronic. CML will account for 4,600 of the chronic cases in 2004.

What are the symptoms of chronic myelogenous leukemia?

The following are the most common symptoms of chronic myelogenous leukemia. However, each individual may experience symptoms differently. Symptoms may include:

The symptoms of chronic myelogenous leukemia may resemble other blood disorders or medical problems. Always consult your physician 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:

Treatment for myelogenous leukemia:

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

Treatment may include:


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