Allogeneic Stem Cell Transplantation in First Complete Remission Enhances Graft-versus-Leukemia Effect in Adults with Acute Lymphoblastic Leukemia: Antileukemic Activity of Chronic Graft-versus-Host Disease

The aim of the present study was to identify graft-versus-leukemia effects and the factors that affect outcome in 201 adults with acute lymphobalstic leukemia who received myeloablative allogeneic stem cell transplantation from matched sibling or unrelated donors (1995-2004). One hundred seventy-eight (88.6%) of these patients had high-risk criteria, and 151 (75.1%) patients were transplanted in first complete remission (CR). All patients received unmodified stem cell grafts (185 bone marrow and 16 peripheral blood) following total- body irradiation-containing myeloablative preparations. Graft-versus-host disease (GVHD) prophylaxis was uniformly attempted by administering calcineurin inhibitor plus methotrexate. After a median follow-up of 63 months (range: 25+ to 139+ months) for surviving transplants, disease-free survival at 5 years was 47.8% for all patients and 60.3% for patients in the first CR. No difference in transplantation outcome was observed between sibling and unrelated transplants in the first CR. The most powerful predictive factor affecting transplantation outcome was disease status at transplantation (the first CR versus beyond the first CR, P < .001). Chronic GVHD (cGVHD), especially limited type, was also found to have a significant antileukemic effect. Interestingly, the influence of cGVHD on relapse risk was prominent in patients with chromosomal translocations or normal cytogenetics.