Low-dose oral etoposide-based induction regimen for children with acute lymphoblastic leukemia in first bone marrow relapse.

We evaluated the clinical response to low-dose etoposide in relapsed acute lymphoblastic leukemia (ALL). Of the 45 patients with ALL in first bone marrow relapse enrolled on the ALL R15 protocol, 44 had received epipodophyllotoxins during frontline therapy. In the first week of remission induction therapy, patients received etoposide (50 mg/m(2) per day) administered orally as a single agent once or twice daily. On Day 8, patients started to receive dexamethasone, vincristine, and L-asparaginase. Etoposide was administered until Day 22. Two courses of consolidation therapy were followed by continuation therapy or hematopoietic stem cell transplantation. After 7 days of single-agent etoposide treatment, peripheral blast cell counts (P=0.013) and percentages of bone marrow blasts (P=0.016) were significantly reduced. In all, 38 (84.4%) attained second remission. Only time to relapse was significantly associated with outcome (P=0.025): the 5-year event-free survival estimates (+/-se) were 52.0+/-9.6% for those with late relapse and 20.0+/-8.0% for those with early relapse. We conclude that low-dose etoposide administered orally has a cytoreductive effect in relapsed ALL.