SUPERIOR PROGNOSIS IN COMBINED COMPARED TO ISOLATED BONE-MARROW RELAPSES IN SALVAGE THERAPY OF CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA

Three hundred twenty-six children with bone marrow (BM) relapse of non -B acute lymphoblastic leukemia (ALL) were stratified according to the time of relapse in three consecutive multicenter trials-ALL-REZ BFM 8 3, 85, and 87. Employing an intensive polychemotherapy regimen, extram edullary involvement appeared to be predictive of superior outcome in both strata as well as in the whole group (probability of 7-year event -free survival (EFS) 42% in combined vs. 15% in isolated BM relapse, P = 0.015). Children with combined BM relapse occurring later than 6 mo nths after completion of front-line therapy reached EFS estimates of 6 0%. We conclude that results of conventional polychemotherapy with BFM relapse protocols are equivalent to those achieved by bone marrow tra nsplantation in children with late combined BM relapse. (C) 1993 Wiley -Liss, Inc.