OVERALL AND EVENT-FREE SURVIVALS FOR ACUTE LYMPHOBLASTIC LEUKEMIA IN CHILDREN AT A SINGLE INSTITUTION IN TAIWAN

The results of treatment for childhood acute lymphoblastic leukemia (ALL) have improved dramatically over the past three decades. The authors present the long-term outcome of patients ( n = 151) with ALL enrolled in 4 consecutive clinical trials conducted from 1982 to 1993 at Mackay Memorial Hospital. During this period, the backbone of the treatment remained relatively unchanged, including a 3- to 4-drug remission induction, central nervous system(CNS)-directed therapy, and cyclic pulses of vincristine and dexamethasone during maintenance therapy. More intensive therapy, consisting of reintensification and addition of more drugs during maintenance, was reserved for high-risk and very-high-risk paitents. The overall survival and event-free survival ( ±1 SE) were 70 ±4.1% and 64 ±4.3%, respectively, with follow-up ranging from 7.6 to 18.7 years (median 12.2 year). The isolated CNS relapse rate was 4.3%. The dropout rate significantaly decreased from 35% in 1982-1984 to 0% in 1991-1993. Although the patient population is small, the overall results for childhood ALL at the authors' hospital are encouraging as compared to earlier reports in Taiwan.