Evaluating the contribution of allogeneic and autologous transplantation to the management of acute myeloid leukemia in adults.

It has been widely accepted that patients in first remission of acute myeloid leukemia (AML) with a donor should receive an allograft, and many also believe that autologous transplantation is the next best option. Several factors cast doubt on these assumptions. For example, it is understood that patients who receive transplants are already selected to be at lower risk of relapse, and in addition the risk of relapse varies considerably among patients. This can be predicted by several risk factors, the most powerful of which is cytogenetics. Major collaborative group trials have attempted to evaluate the contribution of autograft and allograft to AML treatment in CR1. The EORTC-GIEMEMA, GOELAM, UK MRC, and US Intergroup trials randomized approximately 1200 patients to autograft versus, or in addition to, chemotherapy. Although relapse risk was reduced in all studies, overall survival was not better in three of the trials. Only the MRC trial showed a survival benefit, but only in patients beyond 2 years of follow-up. Patients in these trials for whom donors were available were allocated to allogeneic transplant. This enabled the evaluation of allograft in a donor versus no donor (intent-to-treat) analysis. No study showed a survival benefit for the donor arm, although there was a substantial reduction in relapse risk. Analysis within risk groups suggests that transplantation for good-risk patients is not appropriate and the role of transplantation is uncertain in other groups.