Allogeneic bone marrow transplantation for childhood acute lymphoblastic leukemia in second remission: factors predictive of survival, relapse and graft-versus-host disease.

Between 1983 and 1993, 42 patients with acute lymphoblastic leukemia (ALL) in second complete remission (CR) underwent an allogeneic HLA-identical bone marrow transplant (BMT; there was one family mismatched graft). The conditioning regimens varied, consisting of cyclophosphamide (CY) and total body irradiation (TBI; n = 10); CY, TBI, Ara C, VP-16 (n = 11); TBI, Ara C, melphalan (n = 20) (TAM) or other (n = 1). Cyclosporine A (CsA) (n = 15) or CsA and methotrexate (MTX) (n = 24) were the main regimens for prophylaxis of graft-versus-host disease (GVHD). Nineteen of 42 patients are alive in CR ranging from 1 to 72 months after BMT with a median follow-up of 36 months. The 4-year actuarial survival rate was 53%. The actuarial relapse rate was 17%. Twenty three patients died: 4 patients of leukemic relapse, 9 of infection, 2 of acute GVHD, 2 of multiorgan failure after chronic GVHD, 2 of a secondary tumour and 4 patients died of other causes. Several pre- and post-transplant characteristics were analyzed to determine predictive factors for survival, relapse and GVHD. The relapse rate was significantly influenced by the type of conditioning regimen with no relapse in the TBI, Ara C, melphalan group. The analysis of long-term sequelae shows that there are no severe complications in this last group. Our results confirm that allogeneic BMT can lead to long-term survival for children with ALL in second CR and suggest an advantage of using the TAM conditioning regimen in the eradication of the leukemic disease.