Adolescent and young adult Philadelphia negative B cell acute lymphoblastic leukemia: results of the Chilean protocol LLA 15-30

Abstract

Intensified treatment of Philadelphia chromosome negative acute lymphoblastic leukemia (Ph(-)ALL) in adolescents by pediatric teams, with fve years disease free survival (DFS) rate of 65%, encouraged the use of intensified protocols in patients between 15 and 30 years, improving the DFS from 45% to 60-80%. The protocol LLA 15-30 for patients between 15 and 30 years with Ph(-)ALL, based on the Children's Oncology Group (COG) protocol AALL0232 resulting in a five years DFS of 78%, was started in 2007 by the PANDA national program. To report the results of the prospective cohort study evaluating the results of this protocol four years after its implementation. Between January 2007 and December 2010, 68 Ph(-) ALL patients, aged between 15-30 years (75% males) were incorporated. Survival was evaluated using Kaplan-Meier and log-rank tests. Fifty percent of patients were of high risk. A complete response was achieved in 91%, early death occurred in 6% and induction failure in 3%. Median follow-up was 23 months. Overall survival, disease free survival and relapse rates at 35 months were 61.8, 67.5% and 31% respectively. LLA 15-30 protocol significantly improved three-year overall survival from 31 to 62%. The 20% difference observed with AALL0232 protocol is explained by the high rate of relapse. Improving provider and patient compliance with protocols may eliminate this gap.