RESULTS OF TREATMENT OF ACUTE LYMPHOBLASTIC LEUKEMIA IN TWO COHORTS OF MEXICAN PATIENTS Background: GIMEMA ALL 0288 trial was designed to evaluate the impact of a 7-day prednisone (PDN) pretreatment on complete remission of acute lymphoblastic leukemia. We adopted this trial in 2007. Aim: To evaluate the results of treatment in two cohorts of patients with acute lymphoblastic leukemia, treated from 2007 to January 2009 and from February to December 2009. Material and methods: We studied 99 patients treated in the first period (58 males) and 54 patients treated in the second period (33 males) The age of patients ranged from 16 to 60 years and 70% of patients were of high risk. BCR/ABL fusion transcript was present in 12% of patients. Results: Remission rates were 61 and 51% for patients of the first and second group of treatment, respectively. The main cause of death were infections during the induction period. There were 49 relapses, mainly detected in the blood marrow. Global and event free 34 months survival were 32 and 30% respectively. Multivariate analysis disclosed risk stratification and central nervous system infiltration as risk factors for mortality. Conclusions: The main obstacles for the treatment of acute lymphoblastic leukemia in these cohorts of patients were the high incidence of infections and the lack of use of growth stimulating factors.