Long-term results of the Italian Association of Pediatric Hematology and Oncology (AIEOP) acute lymphoblastic leukemia studies, 1982-1995

The first multicentric approach to childhood acute lymphoblastic leukemia (ALL) treatment in Italy started in the early 1970s when the Associazione Italiana di Ematologia ed Oncologia Pediatrica (AIEOP) was founded. Since then the AIEOP has conducted nationwide chemotherapy protocols. Results obtained in three different periods (1982-1986, 1987-1990, 1991-1995) are reported here. Treatment schedules have been characterized by a progressive intensification of systemic therapy and by a progressive substitution of protracted intrathecal therapy for cranial irradiation as central nervous system (CNS) preventive therapy. In the third period cranial radiotherapy (CRT) has been administered only to patients at high risk of relapse or with CNS involvement at diagnosis (about 15% of the overall population). A progressive improvement of therapeutic results, with a steady reduction of isolated CNS relapse rates have been obtained in the three periods considered here. The AIEOP experience shows that CRT can be safely omitted in non-high risk patients, unless they are T-ALL patients with WBC count at the diagnosis greater than or equal to 100 000/mm(3), and that intensification of treatment allows the improvement of overall results with a reduction of the impact of NCI prognostic criteria. Over the years, AIEOP has also continued to foster active cooperation at an international level. In the ongoing AIEOP ALL 2000 study, conducted in cooperation with the BFM group, patients are stratified according to the presence of translocations t(9;22) and t(4;11) and to treatment response (either initial steroid therapy or induction) or minimal residual disease). This cooperation will allow an adequate recruitment of patients to answer relevant randomized questions in the context of a study in which patients are stratified according to minimal residual disease findings.