Allogeneic hematopoietic cell transplantation for adult patients with acute leukemia: the role of meta-analyses.

In spite of decades of research in the field of allogeneic hematopoietic cell transplantation for the treatment of acute leukemia, controversies regarding the role of transplant still exist. These stem not only from contradictory results of different studies, but also from differences in the design and the strength of evidence of the various trials. Meta-analysis is considered the highest level of evidence and as such has the power to resolve clinical issues comparing between different treatment modalities. The aim of this review is to examine the contribution of meta-analyses to the establishment of the role of hematopoietic transplantation for acute leukemia and at the same time to highlight limitations and future directions.