Allogeneic Hematopoietic Stem Cell Transplantation for Adult Acute Lymphoblastic Leukemia: Results from a Single Center, 1993-2011

Abstract

Background: For adult ALL patients, the indications and appropriate timing of allogeneic hematopoietic stem cell transplantation (AHSCT) continue to be debated. The primary aim of this single-institution study was to compare the results of our adult ALL patients that had been allografted with those reported in the current literature. Subjects and Methods: This study included 53 consecutive adults with acute lymphoblastic leukemia (ALL) who underwent allogeneic hematopoietic stem cell transplantation (AHSCT) with myeloablative (92%) and reduced-intensity (8%) conditioning between 1993 and 2011. Results: Mean patient age was 27 years (SD:8.62) and donor age was 33.7 years (SD:9.47). Fourteen patients were in first remission; 21 in ≥2nd remission, 15 in relapse and 3 had primary refractory leukemia. Thirty-four, 15 and 4 patients received busulfan plus cyclophosphamide, cyclophosphamide/total body irradiation and fludarabine-based regimens, respectively. For graft-versus-host disease (GVHD) prophylaxis, cyclosporine plus methotrexate were used. Forty-six donors were related and 7 were unrelated. Thirty patients received granulocyte-colony stimulating factor (G-CSF) mobilized peripheral blood and 23 received bone marrow as stem cell source. Twenty-six patients relapsed at a mean duration of 11.3 months (SD:19.1). Forty-four patients succumbed to their disease after a mean follow-up of 13.6 months (SD:19.5). The cause of mortality was relapse (n=24; 54.5%) and transplant-related etiologies (n=20; 45.5%). The estimated five year probabilities of overall survival (OS) and progression-free survival (PFS) were 37% and 12%, respectively. Conclusion: By multivariate analyses, transplantation in first remission was the most important predictor of transplant success.

Keywords: Acute lymphoblastic leukemia; Allogeneic hematopoietic stem cell transplantation; Overall survival; Progression-free survival.

Figure 1

Kaplan-Meier plot. OS of ALL patients stratified by pretransplant disease status (n=53). ALL patients that underwent transplantation in CR1 predicted a higher OS compared to the other groups (OR: 2.414; 95% CI: 1.56-3.72; p<0.001).

Figure 2

Survival outcomes and progression-free survival of ALL patients (N=53). a: Overall survival data for 53 ALL patients. OS rates were 94%, 75%, 64%, 56%, 47%, 37% and 37% at 1st, 3rd, 5th, 6th, 7th, 13th and 60th month of AHSCT, respectively. b: Progression-free survival data for 53 ALL patients. Rates of PFS were 92%, 71%, 58%, 47%, 45%, 25% and 12% at 1st, 3rd, 5th, 6th, 7th, 13th and 60th months of AHSCT, respectively.