Concept
Chronic myelogenous leukemia (CML), also known as chronic myeloid leukemia, is a cancer of the white blood cells. It is a form of leukemia characterized by the increased and unregulated growth of myeloid cells in the bone marrow and the accumulation of these cells in the blood. CML is a clonal bone marrow stem cell disorder in which a proliferation of mature granulocytes (neutrophils, eosinophils and basophils) and their precursors is found. It is a type of myeloproliferative neoplasm associated with a characteristic chromosomal translocation called the Philadelphia chromosome. CML is largely treated with targeted drugs called tyrosine-kinase inhibitors (TKIs) which have led to dramatically improved long-term survival rates since 2001. These drugs have revolutionized treatment of this disease and allow most patients to have a good quality of life when compared to the former chemotherapy drugs. In Western countries, CML accounts for 15–25% of all adult leukemias and 14% of leukemias overall (including the pediatric population, where CML is less common). The way CML presents depends on the stage of the disease at diagnosis as it has been known to skip stages in some cases. Most patients (~90%) are diagnosed during the chronic stage which is most often asymptomatic. In these cases, it may be diagnosed incidentally with an elevated white blood cell count on a routine laboratory test. It can also present with symptoms indicative of hepatosplenomegaly and the resulting left upper quadrant pain this causes. The enlarged spleen may put pressure on the stomach causing a loss of appetite and resulting weight loss. It may also present with mild fever and night sweats due to an elevated basal level of metabolism. Some (
