[Diagnosis and treatment of chronic myelogenous leukemia]

Chronic myelogenous leukemia is the main diagnosis in case of primitive hyperleucocytosis ou thrombocytosis. The Philadelphia chromosome could be evidenced in the bone marrow by cytogenetic analysis or in the peripheral blood by amplification of the BCR-ABL fusion gene with RT-PCR. A new targeted therapy, imatinib mesylate (Gleevec), inhibits of the dysregulated kinase activity of BCR-ABL. A complete cytogenetic response defined by the absence of Ph+ chromosome in bone marrow is obtained in 85% of cases at the daily dosage of 400 mg. The response is then monitored by quantification of the BCR-ABL transcript. This apparent simple, orally available and well tolerated therapy need to be carefully monitored by real time quantitative PCR in highly specialized laboratories. Allogenic hematopoietic stem cell transplantation remains a curative approach in case of HLA identical donor and is proposed to young patients or in case of imatinib failure. A second generation of BCR-ABL inhibitors is currently in clinical trial.