[End results and comparative analysis of treatment programs for childhood acute lymphocytic leukemia]

The outcome of sixteen treatment programs for childhood acute lymphocytic leukemia reported by cooperative study groups were reviewed and analysed. The rate of disease-free survival for 3 years or more ranged from 34% to 75%, depending on each clinical trial. Remission induction therapy always consists of at least vincristine (V) and prednisone (P). L-asparaginase or daunorubicin is generally added to VP therapy. The following central nervous system (CNS) prophylaxis therapies were compared: craniospinal irradiation cranial irradiation (either 2400 rads or 1800 rads) plus intrathecal methotrexate, intrathecal drugs (either methotrexate alone or so-called triple therapy consisting of methotrexate, cytosine arabinoside and hydrocortisone) and intermediate- or high-dose methotrexate plus intrathecal methotrexate. These therapies have reduced the incidence of CNS leukemia to less than 10%. The intensification phase was the most variable component of treatment. In order to obtain maximum leukemic cell killing early in treatment, a number of protocols are investigating the use of an intensive consolidation course. An early consolidation study by the Berlin-Munster-Frankfurt group in West Germany achieved successful results. However, intensive therapy for low-risk patients failed to improve the disease-free survival. Further studies will be needed to assess the effectiveness of prolonged intensification for patients having any of the prognostic risk features. The standard duration of therapy varies between 2 and 3 years, but the minimum duration of effective chemotherapy is still unknown. It should be clarified whether a more intensive chemotherapy, can facilitate a shorter duration of treatment.