Recent advances in hematopoietic stem cell transplantation for childhood acute lymphoblastic leukemia.

Hematopoietic stem cell transplantation has been an important treatment modality in the management of high-risk or relapsed childhood acute lymphoblastic leukemia. Analysis of its efficacy has been based mostly on stratification of patients by epidemiologic criteria such as disease status at transplantation, type of donor, and conditioning regimens used. The outcome has improved only marginally over the years, with the improvement attributable mainly to better supportive care. Leukemia recurrence remains a major cause of treatment failure. Recent investigations have focused on the biology of the underlying malignancy and on transplant alloreactivity. The results of these investigations may provide a better scientific approach to indications for transplantation, donor selection, and disease monitoring.