Treatment of acute myeloid leukemias in the adult in relapse

Main chemotherapy regimens used to treat adult patients with acute myeloid leukemia (AML) in first or further relapse were reviewed. In retrospective study, second complete remission rates ranged from 30% to 64%, while they ranged from 8% to 89% in prospective trials. The second complete remission rates were closely associated with age and duration of first complete remission. Combination therapies resulted in higher complete remission rates but were associated with higher toxicity. Median duration of second complete remission was < 14 months and overall median survival was < 12 months. The probability of 3-year survival ranged from 8% to 29%. The inhomogeneity of these studies, the differences in dosages and schedules, and the frequent absence of randomisation make it difficult to select the best salvage therapy. No reinduction regimen has so far clearly proven superior. Only stem cell transplantation provided durable remissions for the majority of AML patients after a first relapse. Considering the poor outcomes of patients with AML in first relapse, improved therapies need to be developed. A number of novel agents that include several differentiation agents, enzyme inhibitors, and monoclonal antibodies have been studied to provide improved outcomes for patients with AML who have relapsed. This is the same for acute promyelocytic leukaemia (APL). Arsenic trioxide has shown great promise for the induction, consolidation, and maintenance of complete remission in relapsed patients with APL. Within this context autologous and allogeneic bone marrow transplantations are also considered in second or subsequent relapse. Molecular monitoring for the PML-RARalpha fusion protein permits prompt intervention for early molecular relapse ultimately improving chances of prolonged remission.