Prognostic significance of BCR-ABL rearrangement in childhood acute lymphoblastic leukemia

B a c k g r o u n d . Acute lymphoblastic leukemia (ALL) is the most frequent pediatric malignancy. Presence of adverse risk factors determines risk group stratification in this disease. O b j e c t i v e . The aim of study was the analysis of results of therapy and role of prognostic risk factors in treatment of childhood ALL in kujawsko-pomorskie region in 1995-2010. P a t i e n t s a n d m e t h o d s . During this period, ALL was diagnosed in 223 patients. With respect to time period and therapy protocol, the patients were divided into two groups: group 1 A/B (1995-2002) and group 2 (2002- 2010). Probability of overall survival (OS), event-free survival (EFS) and relapse-free survival (RFS) were analyzed. Uni- and multivariate analyzes for risk factors were performed. R e s u l t s . Over the analyzed 17-year period, OS has increased from 77.9% in group 1A and 73.7% in group 1B to 86.2% in group 2. Results of RFS and EFS have also increased during this time. The death rate has decreased from 26% in group 1A and 26.3% in group 1B to 10.2% in group 2. The most important adverse prognostic risk factors during the first period included involvement of liver, spleen, lymph nodes as well as poor response to initial therapy, while during the second period the most important independent risk factor was BCR-ABL rearrangement in lymphoblasts. C o n c l u s i o n s . The most important independent prognostic risk factors in pediatric ALL include advanced disease, BCR-ABL rearrangement, and initial response to therapy. These factors are used for stratification to treatment groups, intensification of therapy and hematopoietic stem cell transplantation.