Treatment of childhood acute lymphoblastic leukemia after the first relapse: Curative strategies

Background and Objectives. Treatment of recurrent childhood acute lymphoblastic leukemia (ALL) has been controversial in the last decade. Conventional intensive chemotherapy (CHEMO) can cure up to 30% of children who have relapsed after ALL: similar results have been obtained with autologous bone marrow transplantation (ABMT), but allogeneic bone marrow transplantation (AlloBMT) seems to be the best therapeutic option. In this review the authors point out the contribution of current strategy in the setting of children with ALL who experience a first relapse and should be offered optimal treatment in order to obtain the best disease-free survival (DFS). The principal objective of this issue is to reach a possible consensus on the more controversial points regarding factors considered strong predictors of the outcome of the relapsed patients, second-line chemotherapy, optimal timing and type of transplantation. Evidence and Information Source. Data published in the literature over the last decade concerning early and late relapse in childhood ALL suggest that improvements in cure rates may be achieved by intensification of the relapse treatment both with chemotherapy and with different types of transplantation. An accurate search for Medline data has been performed in order to understand the risk-benefit ratio of aggressive therapy adopted in this setting. State of Art. Modern first-line treatment protocols for childhood ALL have contributed to curing an ever larger number of patients but this strategy could be responsible for creating a more resistant leukemic clone at the time of systemic or extramedullary relapse. This hypothesis emerges from a number of single or multicenter experiences; thus clinical and biological features in relapsed patients are being studied crefully in order to understand which risk-directed second-line therapy should be best adopted. The BFM group classified ALL relapses as 'very early', 'early', or 'late' according to the time from diagnosis to first relapse (i.e. 18 and