ALLOGENEIC BONE-MARROW TRANSPLANTATION VERSUS CHEMOTHERAPY IN HIGH-RISK CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA IN FIRST REMISSION

We compared the outcome of children with high-risk acute lymphoblastic leukaemia (HR-ALL) in first complete remission (first CR) treated wit h chemotherapy (CHEMO) or with allogeneic bone marrow transplantation (BMT) in a multicentre study. All children treated by the Italian Paed iatric Haematology Oncology Association for HR-ALL in first CR between 1986 and 1994 were eligible for the study. 30 children were given BMT at a median of 4 months from first CR, with preparative regimens incl uding total-body irradiation (n = 25/30). 130 matched controls for BMT patients were identified among 397 HR-ALL CHEMO patients. Matching on main prognostic factors and duration of first CR was adopted to contr ol the selection and time-to-transplant biases. The comparative analys is was based on the results of a stratified Cox model. The estimated h azard ratios of BMT versus CHEMO at 6 months, 1 year and 2 years after CR were 1.38 (CI 0.59-3.24), 0.69 (CI 0.27-1.77) and 0.35 (CI 0.06-1. 91), with an overall non-significant difference between the two groups (P = 0.34). With a median follow-up of 4 years, the disease-free surv ival was 58.5% (SE 9.3) in the BMT group and 47.7% (SE 4.8) in the CHE MO group, at 4 years from CR, Non-leukaemic death occurred in 4% of CH EMO and 10% of BMT patients. In the BMT group the estimated cumulative incidence of relapse at 1.5 years from CR was 31.5% (SE 8.8) and did not change thereafter, whereas in the CHEMO group the corresponding fi gure was 29.2% (SE 4.1) and the incidence continued to increase therea fter (48.2% (SE 4.8) at 4 years from CR). The results of this study su ggest that, with respect to the CHEMO group, the higher risk of early failure in the BMT group is outweighed by the lower risk of relapse af ter 1 year. Results prompt the need for a prospective study, in order to demonstrate the likely advantage of BMT in HR childhood ALL in firs t CR.