Chronic Myelogenous Leukemia

Chronic myelogenous leukemia (CML)—also called chronic myeloid leukemia—is a slowly progressing blood and bone marrow disease that usually occurs during or after middle age.

Normally, the bone marrow makes blood stem cells that become mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. Myeloid stem cells develop into red blood cells, platelets, or granulocytes (white blood cells).

In the case of CML, too many blood stem cells become myeloblasts, which is a type of immature white blood cell. As these myeloblasts build up in the blood and bone marrow there is less room for healthy white blood cells, red blood cells, and platelets. When this happens, infection, anemia, or easy bleeding may occur.

Most people with CML have a gene mutation called the Philadelphia chromosome. About 9,560 people in the United States were estimated to be diagnosed with CML in 2025 and 1,290 were estimated to die from it, according to the National Cancer Institute.

Chronic Myelogenous Leukemia Treatment (PDQ®)

Source: National Cancer Institute