ALLOGENEIC BONE-MARROW TRANSPLANTATION FOLLOWING A BUSULFAN-BASED CONDITIONING REGIMEN IN YOUNG-CHILDREN WITH ACUTE LYMPHOBLASTIC-LEUKEMIA - A COOPERATIVE STUDY OF THE SOCIETE-FRANCAISE-DE-GREFFE-DE-MOELLE

A subgroup of children with ALL remains at high risk of relapse despit e the administration of intensive chemotherapeutic protocols and may b enefit from allogeneic BMT. The cytoreductive regimen used most often combines TBI with cyclophosphamide. Nevertheless, miscellaneous long-t erm sequelae have been consequent upon radiotherapy, especially in you ng children. This retrospective multicentric study analyzes the outcom e of children with ALL under 4 years of age receiving an HLA-genoident ical BMT following a radiation-free preparative regimen. A busulfan-ba sed regimen with cyclophosphamide or melphalan +/- etoposide +/- cytar abine was given to 21 children (median age: 28 months, range 6-48). Si xteen patients with initial poor prognostic factors were transplanted in first complete response (CR) and five patients in relapse or second CR. With a median follow-up of 47 months, the results show an overall 4-year DFS of 61.1%. Leukemic recurrence was observed in eight patien ts. The preparative regimen was well-tolerated and there were no trans plant-related deaths. A busulfan-based BMT preparative regimen may be a therapeutic alternative to TBI-containing regimens in young children . Efforts are currently aimed at reducing the relapse rate in these ch ildren by optimizing the tumoricidal potential of chemotherapy and the graft-versus-leukemia effect of allogeneic BMT.