Chronic Myelogenous Leukemia Clinical Practice Guidelines in OncologyNCCN Categories of Evidence and ConsensusCategory 1: The recommendation is based on high-level evidence (e.g., randomized controlled trials) and there is uniform NCCN consensus.Category 2A: The recommendation is based on lower-level evidence and there is uniform NCCN consensus.Category 2B: The recommendation is based on lower-level evidence and there is nonuniform NCCN consensus (but no major disagreement).Category 3: The recommendation is based on any level of evidence but reflects major disagreement.All recommendations are category 2A unless otherwise noted.Clinical trials: The NCCN believes that the best management for any cancer patient is in a clinical trial. Participation in clinical trials is especially encouraged.OverviewChronic myelogenous leukemia (CML) accounts for 15% of adult leukemias. Although the median age of disease onset is 67 years, CML occurs in all age groups (Surveillance, Epidemiology, and End Results [SEER] statistics). In 2009, an estimated 5050 cases will be diagnosed and 470 patients will die from the disease in the United States.1CML is a hematopoietic stem cell disease, which is characterized by a reciprocal translocation between chromosomes 9 and 22, resulting in the formation of the Philadelphia chromosome (Ph chromosome). This translocation t(9;22) results in the head-to-tail fusion of the breakpoint cluster region (BCR) gene on chromosome 22 at band q11 and the Abelson murine leukemia (ABL) gene located on chromosome 9 at band q34.2 The product of the fusion gene (BCR-ABL) is believed to play a central role in the...