Chronic Myeloid Leukemia

Abstract

Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, chronic myelocytic leukemia, and chronic granulocytic leukemia, is characterized by the expansion of myeloid progenitor cells at various stages of maturation, their premature release into the circulation, and a tendency to home to extramedullary sites. Symptoms at presentation reflect the increase in mass and turnover of the leukemic cells, although as many as 50% of patients are asymptomatic at diagnosis and come to attention through unexpected findings on routine blood tests. In treatment, the ongoing development of established and novel tyrosine kinase inhibitors (TKIs) has made for closer to normal life spans in patients diagnosed with CML. This review serves as an overview of CML, detailing its epidemiology and etiology, pathophysiology, diagnosis, treatment (including an assessment of the latest clinical trials involving TKIs), and management of patients with advanced phases. Figures show BCR-ABL signaling pathways and mechanisms of resistance to imatinib. Tables list stages of CML, differential diagnosis of CML and Philadelphia chromosome–negative myeloproliferative disorders, a summary of pivotal phase III trials of approved TKIs for the treatment of front-line or relapsed CML, response evaluation to TKIs used as first-line therapy, and a summary of important phase II trials of second- and third-generation TKIs after previous TKI failure. This review contains 2 highly rendered figures, 5 tables, and 87 references.