Comparison of the results of the treatment of adolescents and young adults with standard-risk acute lymphoblastic leukemia with the Programa Español de Tratamiento en Hematología pediatric-based protocol ALL-96.

Retrospective studies have shown that adolescents and young adults with acute lymphoblastic leukemia (ALL) treated with pediatric protocols have better outcomes than similarly aged patients treated with adult protocols, but prospective studies comparing adolescents and young adults using pediatric schedules are scarce. The ALL-96 protocol was addressed to compare the toxicity and results of a pediatric-based protocol in adolescents (age 15-18 years) and young adults (age 19-30 years) with standard-risk (SR) ALL. Adolescents (n = 35) and young adults (n = 46) received a standard five-drug/5-week induction course followed by two cycles of early consolidation, maintenance with monthly reinforcement cycles up to 1 year in continuous complete remission (CR) and 1 year with standard maintenance chemotherapy up to 2 years in CR. Adolescents and young adults were comparable in the main pretreatment ALL characteristics. The CR rate was 98% and. after a median follow-up of 4.2 years, 6-year event-free survival (EFS) and overall survival (OS) were 61% (95% CI, 51% to 72%) and 69% (95% CI, 59% to 79%), respectively, with no differences between adolescents and young adults. The hematologic toxicity in consolidation and reinforcement cycles was higher in young adults than in adolescents. Slow response to induction therapy was the only parameter associated with poor EFS (34% v 67%) and OS (40% v 76%). The response to the pediatric ALL-96 protocol was identical in adolescents and young adults despite a slight increase in hematologic toxicity observed in adults. This justifies the age-unrestricted use of pediatric regimens to treat patients with SR ALL.