Molecular Profiling of Chronic Myeloid Leukemia
Chronic myeloid leukemia (CML; also known as chronic myelogenous leukemia) is an uncommon cause of cancer-related mortality in the United States, with an estimated 8,430 new cases and 1,090 deaths anticipated in 2018 (ACS 2018; NCI 2012).
CML is characterized by the presence of the Philadelphia chromosome, a translocation between chromosomes 9 and 22 in humans, resulting in a fusion between the 5’ end of the BCR gene and the 3’ end of the ABL1 gene. The Philadelphia chromosome was discovered in 1960, but the molecular genetic features were not understood until more recently. In the 1980s it was discovered that the Philadephia chromosome resulted in the BCR-ABL1 fusion gene (Koretzky 2007).
Prior to the approval of imatinib in 2001, CML was treated using interferon-alpha or bone marrow transplant. Since then, imatinib and several additional ABL1 kinase inhibitors have become the most common treatments for CML.
Although the Philadelphia chromosome may be found in other types of leukemias, presence of a BCR-ABL1 fusion gene is an absolute diagnostic criterion for CML, so it is present in all cases. Point mutations in ABL1 can confer resistance to ABL1 kinase inhibitors used to treat CML.
Suggested Citation: Shaver, A., M. Jagasia. 2018. Molecular Profiling of Chronic Myeloid Leukemia. My Cancer Genome https://www.mycancergenome.org/content/disease/chronic-myeloid-leukemia/ (Updated March 16).
Last Updated: March 16, 2018