Chronic myeloid leukaemia

Chronic myeloid leukaemia (CML) is a malignant clonal disorder of haematopoietic stem cells.

At presentation, approximately 50% of patients may be asymptomatic. Symptoms, if present, typically include malaise, fever, weight loss, abdominal discomfort, and night sweats.

Splenomegaly is the most common physical finding; nearly all patients will have elevated WBC count.

Presence of Philadelphia chromosome and/or molecular demonstration of the BCR::ABL1 transcript confirms diagnosis.

Treatment with a tyrosine kinase inhibitor (TKI) gives long-term remission without significant adverse events in most patients.

Treatment-free remission may be attempted for select patients, and thus functional cure after TKI therapy is feasible.

CML is a malignant clonal disorder of the haematopoietic stem cell that results in marked myeloid hyperplasia of the bone marrow.[1]Sawyers C. Chronic myeloid leukemia. N Engl J Med. 1999 Apr 29;340(17):1330-40. http://www.ncbi.nlm.nih.gov/pubmed/10219069?tool=bestpractice.com Dysregulation of haematopoiesis arises due to a BCR::ABL1 fusion gene that causes an abnormal expansion of myeloid cells in the bone marrow and peripheral blood. The 'chronic' phase of the disease may transform to an 'accelerated' or 'blast' phase in 5% to 10% of patients despite treatment with a tyrosine kinase inhibitor, the blast phase resulting in acute myeloid or acute lymphoblastic leukaemia.[2]Hochhaus A, O'Brien SG, Guilhot F, et al. Six-year follow-up of patients receiving imatinib for the first-line treatment of chronic myeloid leukemia. Leukemia. 2009 Jun;23(6):1054-61. http://www.ncbi.nlm.nih.gov/pubmed/19282833?tool=bestpractice.com [3]Druker BJ, Guilhot F, O'Brien SG, et al; IRIS Investigators. Five-year follow-up of patients receiving imatinib for chronic myeloid leukemia. N Engl J Med. 2006 Dec 7;355(23):2408-17. https://www.nejm.org/doi/full/10.1056/NEJMoa062867 http://www.ncbi.nlm.nih.gov/pubmed/17151364?tool=bestpractice.com