ABSTRACT
PURPOSE: In 1970, the Berlin-Frankfurt-Munster(BFM) group introduced an intensification therapy after remission induction to reduce relapse of acute lymphoblastic leukemia(ALL) in childhood. Delayed intensification(DI) phase has been included for treatment of ALL in our hospital since the mid-1990s. The purpose of this study is to evaluate the outcome with vs. without DI phase and the outcome with two vs. one DI phase for intermediate risk patients. METHODS: One hundred and thirty nine children with ALL who were treated at the Department of Pediatrics of Wonju Christian Hospital and Yonsei University Medical Center between March, 1990 and July, 2002 were analysed retrospectively. RESULTS: Thirty-eight patients were treated with a DI phase, and 101 patients were treated without a DI phase. Among the DI patients, seven patients were treated with a double DI phase. Five-year overall survival(OS) in the low, intermediate, and high risk groups were 68%, 66% and 58%, respectively. 5-year OS in DDI, DI, and control were 95%, 86% and 40%, espectively. In the low risk group, 5-year event free survival(EFS) in DI, and control were 94% and 58%, respectively. CONCLUSIONS: Delayed intensification improved EFS on childhood ALL in all risk groups.