Treatment strategies in acute myeloid leukemia (AML). B. Second line treatment.

The strategy for treatment of relapsed or refractory acute myeloid leukemia must primarily be based on the patient's age and clinical condition as well as on the stage of the disease. Accordingly, the general decision between an intensive approach including high-dose chemotherapy or possibly immediate allogeneic bone marrow transplantation versus less-aggressive palliative treatment will precede the selection of the most appropriate salvage regimen. In patients qualifying for intensive second-line chemotherapy the duration of the first remission and the number of relapses provide the means to discriminate between refractoriness or maintained responsiveness to conventional protocols. More than 50% of patients with first relapses after 6-12 months remission duration will respond to standard therapy again and should therefore not be entered on investigational agents with unproven antileukemic activity. The latter seems deeply warranted, on the other hand, for early relapses, second recurrences and resistant first relapses with a remission rate of less than 30% after conventional regimens. These guidelines not only provide an objective rationale for selecting the most appropriate strategy at relapse in individual patients. Furthermore, they facilitate interstudy comparisons and a better judgement of different treatment protocols.