Bone marrow transplantation for acute leukemias

Abstract

Bone marrow transplantation represents an effective therapy for acute myelogenous leukemia. Despite its initial use in patients in late stages of their disease, the best results have been documented when the procedure is undertaken while in first complete remission. Recent advances in the management of the neutropenic patient have guaranteed the safe use of aggressive chemoterapy regimens, resulting in a prolonged disease free survival, similar to what is documented after myeloablative regimens. Doubts still remain as of which patients should be submitted to marrow transplantation and at which stage of their disease. Cytogenetics and a better definition of other biological characteristics will allow a better selection of patients. The control of graft versus host disease, improvement in the management of infectious complications, the use of nonmyeloablative conditioning regimens and a greater availability of unrelated marrow donors will permit a greater use of allogeneic marrow transplantation in acute myelogenous leukemia, including elderly patients. The role of autologous transplantation must be better defined. On the other hand, bone marrow transplantation in acute lymphoblastic leukemia remains a controversial issue. In adults, the results of conventional therapy are, in general, inferior to those obtained in childhood. Nevertheless, prospective comparative studies have failed to demonstrate a clear superiority for patients transplanted in first remission. Cytogenetic alterations are useful in the definition of prognostic groups, but other biological features must be defined for a better selection of patients. In advanced stages of the disease, allogeneic transplant remains the sole alternative with curative potential but relapse remains a serial limitation of the procedure.The results with autologous transplantation must be confirmed in better controlled studies and the use of unrelated tranplants is acquiring greater importance, due to the easier identification of potential donors. In childhood, the excellent results obtained with traditional chemotherapy indicate the need of very rigorous selection of extreme high risk patients that might benefit from the procedure. However, these groups of patients must be better defined.