BONE-MARROW TRANSPLANTATION VERSUS CHEMOTHERAPY FOR MAINTENANCE OF 2ND REMISSION OF CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA - A STUDY OF THECHILDRENS-CANCER-GROUP (CCG-1884)

Background. Maintenance of second remission of childhood acute lymphob lastic leukemia (ALL) with intensive chemotherapy is often unsuccessfu l. The major cause of treatment failure is relapse. Materials and Meth ods. Of 96 children with ALL who relapsed in the marrow while on or wi thin 1 year of completing initial therapy, 62 achieved a second remiss ion. Nineteen patients underwent bone marrow transplantation in second remission, 11 from a human leukocyte antigen (HLA)-matched related do nor, seven using autologous marrow, and one from a matched unrelated d onor. The event-free survival (EFS) of transplanted patients was compa red to that of patients treated with intensive chemotherapy using. hig h-dose cytarabine, vincristine, escalating dose methotrexate, L-aspara ginase, and an anthracycline (daunorubicin or idarubicin). Only those patients treated with chemotherapy who survived in second remission up to the mean time that patients were transplanted (135 days) were incl uded in the control group (33 of 43 patients who achieved second remis sion). Results. The actuarial 2-year event-free survival of transplant ed patients is 37 +/- 22% (95% C.I.) compared to 18 +/- 13% for chemot herapy-treated patients (P = 0.017). EFS for allo-transplant recipient s was similar to that for auto-transplant recipients. Duration of init ial remission was a strong predictor of the outcome of retrieval thera py. Patients whose initial remission was greater than 3 years had bett er EFS after achieving second remission (five of 11 still in remission , compared to four of 41 patients whose initial remission was less tha n 3 years). Adjustment in the multivariate analysis for duration of in itial remission did not diminish the benefit oi transplant over chemot herapy. Conclusions. While there remains considerable possibility for further improvement in EFS alter achieving second remission of childho od ALL, bone marrow transplant is superior to chemotherapy in maintain ing second remission. (C) 1997 Wiley-Liss, Inc.