Chemotherapy and bone marrow transplantation in the treatment of chronic myelogenous leukemia

Many therapeutic modalities have been or are being investigated for the management of chronic myelogenous leukemia (CML). Conventional chemotherapy with hydroxyurea or busulfan continues to be the most widely prescribed modality. Recent data suggest that hydroxyurea is preferred over busulfan on the basis of survival rates, particularly among patients who undergo bone marrow transplantation. To improve on responses associated with interferon-alfa (IFN-alpha) alone, IFN-alpha has been added to drugs with selective activity against CML. Combining low-dose cytosine arabinoside and IFN-alpha improves outcome in patients with late chronic-phase CML. Preliminary results with homoharringtonine as induction therapy followed by the addition of IFN-alpha as maintenance therapy are also promising in patients with early chronic-phase CML. Enthusiasm regarding allogeneic bone marrow transplantation remains high, but there are problems related to paucity of ideal candidates, controversies regarding optimal timing, and some mortality. Interferon-alfa has been used in the immediate posttransplant period to reverse early cytogenetic relapse in a limited number of patients, which suggests that IFN-alpha also may be useful in preventing relapse in high-risk patients. In autologous bone marrow transplantation, there is interest among investigators in reducing the leukemic burden and altering the marrow microenvironment to favor normal hematopoiesis, but the effect of this alternative on survival is not yet known. Results suggest that young patients are candidates for allogeneic bone marrow transplantation, whereas older patients should be offered IFN-based therapy initially.