Allogeneic Bone Marrow Transplant in Pediatric Patients with High-Risk Hematopoietic Malignancies Early in the Course of Their Disease

Abstract
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 fractionated total body irradiation (FTBI) and etoposide (VP-16). Those studied were 33 patients aged < or =18 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/kg) as a preparatory regimen for BMT from matched sibling donors. Patients with acute leukemia included 18 with acute nonlymphocytic leukemia (ANLL), one with biphenotypic acute leukemia (BAL), and 10 with selected "high-risk" acute lymphocytic leukemia (ALL). Patients with ALL were selected for a high risk for recurrence: those who failed standard remission induction chemotherapy, had a t(9;22) or t(4;11) chromosomal translocation, or had certain clinical high-risk features. At the time of analysis, 28 patients are alive, all of them in continued 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 surviving patients have a performance status of >80%. This result of early BMT in a two-institution study of pediatric patients with hematopoietic malignancies suggests that (a) matched sibling allogeneic BMT after conditioning with FTBI and high-dose VP-16 is an excellent treatment for pediatric patients with high-risk leukemia, and (b) children may have a better prognosis than adults treated with allogeneic BMT. Larger multiinstitutional cooperative trials for pediatric patients are needed to confirm this result.