[Recent progress in the treatment of acute leukemia]

Acute leukemia is classified broadly as either acute myelogenous leukemia (AML) or acute lymphoblastic leukemia (ALL). The main treatments remain remission induction therapy and postremission chemotherapy. The advances in chemotherapy for pediatric patients with ALL have been dramatic, with some 95% achieving complete remission, and long-term survival is 60-80%. Among adults, high long-term survival rates due to improvements in chemotherapy for B-cell type ALL and core binding factor leukemias have been reported. For adult leukemias overall, however, long-term survival rates have stalled at 15-40% despite the high remission rate attained. In most cases this is due to a recurrence. Among the prognostic factors reported for acute leukemia, chromosome type may be cited as the currently most reliable. Acute leukemia patients are classified based on chromosome type, and the postremission therapeutic strategy is considered in terms of an appropriate combination of chemotherapy and hematopoietic stem cell transplant. This accounts for an important part of the treatment given today. Target-based therapies such as all-trans-retinoic acid (ATRA) for AML have brought dramatic improvements in treatment results. The effect of imanitib against Philadelphia chromosome positive ALL, for which the prognosis is poor, is also attracting attention. Moreover, promising new treatment strategies that have been developed, including cord blood transplant, mini-transplant, antibody therapy, and immunotherapy, Clinical studies of PCR and other means to reveal small residual lesions and estimate prognosis are also making progress. In the future it will be possible to identify prognostic factors in genetic tests such as DNA microarrays and single nucleotide polymorphisms, so that the optimum treatment can be selected for individual patients.