Allogeneic stem Cell Transplantation outcome in acute Lymphoblastic Leukemia Patients

Abstract

Introduction: Despite achievement to complete remission (CR) with current treatments and new multiple chemotherapeutic agents in Acute Lymphoblastic Leukemia (ALL) patients, the majority of them still relapse during long-term follow-up. The use of post- remission therapy will reduce early relapse in these cases, but the best option is still debatable.
Patients and Methods: In this retrospective review, we assessed the outcome of allogeneic hematopoietic stem cell Transplantation (HSCT) in ALL patients treated in our center. All cases received cyclophosphamide and busulfan as conditioning regimen, cyclosporine A and methotrexate for graft versus host disease prophylaxis (GVHD) and trimethoprim/sulfamethoxazole, acyclovir and fluconazol as prophylaxis of bacterial / viral and fungal infections.
Results: From March 1991 till August 2011, 446 ALL patients with a median age of 20 (range: 2 -53) years old underwent allogeneic HSCT. The male to female ratio was 300/146. At the time of transplantation 63 % of cases were in first CR, 23 % in second CR and 6% in third CR. Thirty eight (9%) patients were transplanted in primary induction failure or relapse. Sources of hematopoietic stem cell included peripheral blood (n=412, 92.3%), bone marrow (n=23, 5.1%), cord blood (n=8, 1.7%) and peripheral blood with bone marrow (n=3, 0.9%). Almost 93.2% of patients received stem cells from their HLA- identical siblings. HLA-mismatched sibling or other relatives, HLA-matched other relative and HLA-mismatched unrelated donors were 3.4%, 2% and 1.4%, respectively. Female patients received stem cells from 16% of female and 17% of male donors. Male patients received stem cells from 26% of female and 41% of male donors. The median time of neutrophil recovery was16 (range: 6-58) days and platelet recovery was 12 (range: 9-43) days. Relapses occurred in 106 (24%) patients. 18-month LFS and OS were 58.9% (SE: 2.6%) and 68.1% (SE: 2.5%), respectively.
Conclusion: According to these results, allogeneic HSCT as a post- remission therapy can improve OS and DFS in ALL patients with a reduction in relapse rate.