RESUMEN
The outcome of 63 children with non-B acute lymphoblastic leukemia treated with ALL-BFM 83 protocol is analyzed. 95% achieved complete remission with the initial treatment. For the entire group the event free survival (EFS) was 66% (+/- 9%) at 48 months. These results were close to those obtained by the BFM group. Haematological toxicity was the main adverse effect, but there where no therapy related deaths. Persistence of more than 1,000 blast cells per microl in peripheral blood after 7th days of prednisone monotherapy, and spleen size greater than or equal to 5 cm under the costal margin, were identified as independent risk factors of high significance. The EFS in patients with poor clinical response to steroids (greater than or equal to 1,000 blast/microl at day 8) was 22% (+/- 18%), instead of 69% (+/- 12%) in those with adequate response.