A NEW CHALLENGE IN CLINICAL RESEARCH IN CHILDHOOD ALL - THE PROSPECTIVE METAANALYSIS STRATEGY FOR INTERGROUP COLLABORATION

We consider the problems arising in clinical research on childhood acu te lymphoblastic leukemia (ALL). Given the therapeutic progress achiev ed over the last few decades, any improvement in the outcome for the m ajority of children with ALL is difficult to assess with the usual siz e trials. Furthermore, the progress in genetics and molecular biology has now led to the identification of subgroups of children, typically with rare characteristics, for whom new treatments still await evaluat ion. For both these aspects of clinical research, there is an increasi ng need for international intergroup cooperation. After a discussion o n the role of retrospective meta-analysis and randomized controlled tr ials in ALL research, we suggest that intergroup studies could be made more feasible, but still scientifically rigorous, by adopting a strat egy of prospective meta-analysis. This strategy can be described as fo llows: i) different groups prospectively plan to ask the same randomiz ed question within their protocols which may differ in other aspects, and to pool their data in order to evaluate treatment effect; ii) the management of the study can be de-centralized, by allowing each group to be responsible for conducting its own protocol. We would like to st imulate the debate on the methodological and practical aspects of rese arch perspectives in ALL (and in pediatric oncology).