Treatment of childhood acute lymphoblastic leukemia (ALL) according to the protocol ALL-BFM 95 was performed at 8 departments of pediatrics between 1996-2002 in the Czech Republic. Patients were stratified into 3 risk groups (standard risk-SR, medium risk-MR and high risk-HR) according to the early treatment response, age, initial WBC and the finding of translocations t(9;22) or t(4;11).
Total duration of treatment was 2 years except for boys of SR for whom it was three years. 386 children were enrolled into the study and the treatment results were evaluable in 380 patients with a median follow-up of 8.2 years. Complete remission (CR) was achieved in 95.5% pts, 3.9% children died in CR.
Stratification into the risk groups was as follows: SR 32.4%, MR 53.7% and HR 13.9%. 69 children (19%) suffered from relapse, isolated CNS relapse has been diagnosed only in 1.1%. Two children (0.6%) developed secondary cancer.
Event-free survival (EFS) is 73.1% and overall survival (OS) 80.8%. The results improved in comparison with previous study ALL-BFM 90 (EFS 71.3%; OS 76.4%) despite treatment reduction for 2/3 of patients.
EFS/OS were in SR 84.5/93.2%, MR 74/82.1% and HR 43.1/47.1%. The prognosis of T-ALL (EFS 64.8%) was significantly worse in comparison with BCP-ALL (EFS 75.8%).
Only 7 children underwent stem cell transplantation in the first CR. Survival of children with ALL in the Czech Republic exceeded 80%.
Significant improvement was particularly achieved in HR group (EFS in previous study only 28.2%).