[New trends in the treatment of leukemia]

More than 50% cure can be obtained with allogeneic bone marrow transplantation (BMT) when patients are transplanted in first remission of AML and ALL or chronic phase of CML. On the other hand, considerable progress has been made recently in treating acute leukemia with chemotherapy. Recent studies of intensive chemotherapy in adults with AML report approximately 40-50% 3-year disease-free survival (DFS). Accordingly, several prospective randomized clinical trials have been conducted on the use of BMT versus intensive chemotherapy in the treatment of AML. Significant differences in DFS were found only in a few studies though the results of BMT appear to be comparable or superior to chemotherapy. Therefore, the overall advantage of BMT in first remission AML is smaller than expected. We should know not whether to transplant or to perform chemotherapy, but rather whether to transplant in first remission or to perform chemotherapy first and reserve transplantation as salvage therapy. Recently acute promyelocytic leukemia has been successfully treated with differentiation therapy using all-trans retinoic acid. Low-dose aclarubicin has also been reported to be effective as differentiation therapy in some patients with myelodysplastic syndrome and atypical AML. With the advance of molecular biology of cytokines, several of them are now available for clinical use. G-CSF, GM-CSF and M-CSF are potent stimulators for the granulocyte-macrophage production; they are very effective for accelerating hematologic recovery after chemotherapy-induced myelosuppression or BMT. Interferon-alpha (IFN-alpha) has been used in the several studies. Furthermore, Ph chromosome positivity can be reduced with long-term administration of IFN-alpha; Ph-positive clone can be undetectable in some patients. Thus, IFN-alpha will be the choice of treatment for CML even if BMT is planned.