Comparison of outcomes of children with acute lymphoblastic leukemia treated with BMF protocol across 2 decades

Acute lymphoblastic leukemia is the most common malignancy of childhood. The aim of this study is to compare the outcome of children with acute lymphoblastic leukemia treated with BFM protocol over two decades at our center. We retrospectively examined the files of 421 patients by dividing them into two groups by decade of treatment, 1995-2005 and 2006-2015. After excluding 117 patients, overall, 304 patients were included in the analysis. From the first to the second decade, the proportion of patients over 12 years of age increased from 7.1% to 16.8% (p < 0.04), the high-risk group increased from 15.5% to 19.5% and patients with central nervous system leukemia increased from 5.2% to 11.4%. The relapse rate remained relatively unchanged during this period (from 12.9% to 12.7%), while the mortality rate decreased from 18.7% to 15.4% (p > 0.05) and the death rate during remission induction treatment decreased from 3.9% to 0.7%. The mortality rate of high-risk and standard-risk patients decreased from 62.5% to 34.5% (p < 0.05) and 11.1% to 3.0% (p > 0.05), respectively. The 5-year overall survival and event-free survival rates for standard-, medium- and high-risk patients were 92.7% +/- 6.0%, 87.9% +/- 4.7%, and 54.7% +/- 13.3% and 92.5% +/- 6.3%, 83.2% +/- 5.5%, and 48.7% +/- 14.7%, respectively. For the cohort, the 5-year overall survival rate was 83.2% +/- 4.1% and the event-free survival rate was 79.9% +/- 4.7%. These results demonstrate the impact of a standard protocol, experience of staff, achieving better risk stratification on treatment success.