ABSTRACT
Allogeneic hematopoietic stem cell transplantation (HCT) is currently the only treatment proven to cure chronic myelogenous leukemia (CML). Despite excellent response rates with few toxicities with imatinib, trials with this drug only began in 1998. The longest follow-up is now less than 10 years and there are relatively few patients who were followed more than five years on this therapy. The general procedure for allogeneic HCT is to administer high (marrow ablative) doses of chemotherapy with or without radiation to eradicate leukemia cells, followed by the infusion of healthy hematopoietic stem cells to restore hematopoiesis. Second hematopoietic stem cell transplantation with full or reduced intensity conditioning is sometimes used for post-transplant relapse, but is associated with high rates of transplant-related mortality, especially if the interval between the first and second transplant is less than one year. This approach is generally reserved for young patients who relapse with accelerated or blast phase CML more than a year after a first transplant.
