Autologous stem cell transplantation for the treatment of chronic myelogenous leukemia.

Abstract

Chronic myleogenous leukemia (CML) is a malignant disorder arising from the hematopoietic stem cell. It is characterized by abnormal expansion of malignant hematopoietic progenitor and precursor cells with concomitant suppression of normal hematopoiesis. CML is characterized cytogenetically by the 9;22 translocation resulting in the characteristic Philadelphia chromosome (Ph) [1] and, at the molecular level, the bcr/abl fusion oncogene [2]. Several studies have demonstrated a critical role for the bcr/abl oncogene in the pathogenesis of CML [3]. In contrast to other leukemias, treatment with conventional chemotherapy usually fails to induce a persistent complete cytogenetic remission in CML, and does not alter the course of the disease or prevent progression to accelerated phase (AP) and blast crisis (BC) over a median of 3 to 5 years. Allogeneic bone marrow transplantation using HLA-matched sibling or unrelated donor marrow is at present the most effective therapy for CML and successfully eliminates the malignant clone in a large proportion of patients. However, allogeneic transplants are available to less than 50% of CML patients either because of lack of a suitable donor or because older patients are unable to tolerate the associated morbidity and mortality. In view of this, there is a clear need to develop alternative therapeutic strategies.