Front-Line Treatment Options for Chronic-Phase Chronic Myeloid Leukemia

A 40-year-old woman with a past medical history of hypertension and occasional premature ventricular contractions was found on routine blood work in June 2011 to have mild thrombocytosis, with a platelet count of 405,000. In November 2011, repeat analysis revealed a platelet count of 433,000, and by February 2012 her platelet count was 509,000. She had no evidence of leukocytosis or anemia and no symptoms of early satiety, night sweats, pruritus, or erythromelalgia. She was referred to a hematologist for evaluation of persistent isolated thrombocytosis in March 2012. Her spleen was not palpable, and a quantitative polymerase chain reaction (PCR) test for JAK2/V617F was negative. A bone marrow biopsy and aspiration revealed a mildly hypercellular marrow (70% to 80% cellularity), with an elevated myeloid: erythroid ratio of 5: 1, increased megakaryocytes including micromegakaryocytes in the absence of increased blasts. Cytogenetic analysis revealed the presence of the Philadelphia chromosome translocation in 17 out of 20 metaphases. The remaining three metaphases were normal karyotype. Quantitative PCR for BCR-ABL1 yielded a value of 29.6% on the International Scale.