ALLOGENEIC BONE-MARROW TRANSPLANT IN PEDIATRIC-PATIENTS WITH HIGH-RISK HEMATOPOIETIC MALIGNANCIES EARLY IN THE COURSE OF THEIR DISEASE

Purpose: The purpose of this study was to investigate the role of bone marrow transplant (BMT) early in the course of disease for pediatric patients with high-risk leukemia using a preparatory regimen of fracti onated total body irradiation (FTBI) and etoposide(VP-16). Patients an d Methods: Those studied were 33 patients aged less than or equal to 1 8 years with either acute leukemia in first complete remission (CR) (n = 29) or chronic myelogenous leukemia (CML) in first chronic phase (n = 4) who received 1,320 cGy FTBI followed by high-dose VP-16 (60 mg/k g) as a preparatory regimen for BMT from matched sibling donors. Patie nts with acute leukemia included 18 with acute nonlymphocytic leukemia (ANLL), one with biphenotypic acute leukemia (BAL), and 10 with selec ted ''high-risk'' acute lymphocytic leukemia (BAL). Patients with ALL were selected for a high risk for recurrence: those who failed standar d remission induction chemotherapy, had a t(9;22) or t(4;11) chromosom al translocation, or had certain clinical high-risk features. Results: At the time of analysis, 28 patients are alive, all of them in contin ued complete remission for 1.1-7.8 years (median, 5.3 years; mean, 4.9 years). The Kaplan-Meier projected event-free survival (EFS) is 84.5% at 7 years, and the actuarial recurrence hazard is 6.5%. All survivin g patients have a performance status of >80%. Conclusion: This result of early BMT in a two-institution study of pediatric patients with hem atopoietic malignancies suggests that (a) matched sibling allogeneic B MT after conditioning with FTBI and high-dose VP-16 is an excellent tr eatment for pediatric patients with high-risk leukemia, and (b) childr en may have a better prognosis than adults treated with allogeneic BMT . Larger multiinstitutional cooperative trials for pediatric patients are needed to confirm this result.