Prognostic factors affecting leukemia relapse after allogeneic BMT conditioned with cyclophosphamide and fractionated TBI.

Between June 1985 and May 1992, 94 consecutive patients with acute myeloid leukemia (AML = 28), acute lymphoblastic leukemia (ALL = 27) and chronic myelogenous leukemia (CML = 39), were transplanted using genotypically HLA-identical marrow donors. All were conditioned with cyclophosphamide (CY) plus 12 Gy fractionated TBI. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A alone in nine patients and methotrexate-cyclosporin A in 85 patients. Forty-eight patients developed grades II-IV acute GVHD and 24 of 68 patients who survived at least 100 days developed chronic GVHD. The 5-year actuarial probability of survival, event-free survival and relapse were 41 +/- 5%, 37 +/- 5% and 37 +/- 6%, respectively. In multivariate analysis, an increased risk of leukemia relapse was associated with (1) absence of chronic GVHD (P = 0.017), (2) advanced disease at transplant (P = 0.034) and (3) diagnosis of AML (P = 0.047). Our results confirm that disease status at transplant and chronic GVHD are the more important risk factors associated with leukemia relapse, and suggest that CY-TBI has only a partial role in eradicating leukemia in AML.