Allogeneic hematopoietic stem cell transplantation for adults with acute lymphoblastic leukemia

Advances in chemotherapy over the last four decades have dramatically improved the outcomes of children with acute lymphoblastic leukemia (ALL). In contrast, only 35-40% of adults with ALL survive 5 years. Most adults with ALL achieve complete remission (CR) with multidrug induction chemotherapy, yet the high relapse rate poses the major obstacle to cure. Allogeneic donor hematopoietic stem cell transplantation (HCT) can offer a unique anti-leukemia effect and potential for extended disease-free survival (DFS) for adults with ALL. Large studies have demonstrated improved survival for allogeneic HCT in first remission for patients with high-risk ALL and after first relapse in all adults. The growing understanding of the biology and pathogenesis of ALL and the use of newer cytogenetic, molecular, genetic, and monitoring techniques may better predict risk of relapse in ''standard''-risk ALL patients and identify patients who can benefit from an intensified transplant approach. The current state of knowledge of myeloablative allogeneic HCT for ALL, timing and donor choice, improvements in transplantation process, along with growing experience with unrelated donor (URD) and umbilical cord blood (UCB) allografts is reviewed here.