The Medical Research Council trials in adult acute lymphocytic leukemia

Overall, the MRC Adult Leukaemia Trials have been successful, in that since the 1970s they have demonstrated a stepwise improvement in outcome. Examination of the survival curves shows the DFS rate at 5 years in UKALL Trial 1 of 5% rising to 38% in UKALL Trial XII (year 2000). Unfortunately, compared with children with ALL, these results in adults must be regarded as poor, because in the UKALL children's trials the EFS rate at 5 years for a child entered in the year 2000 is expected to be above 80%. With a low proportion of all adults entered into randomized trials, one cannot be certain that improvements result from treatment rather than patient selection. Only recently have randomized trials in adults become large enough to detect plausible treatment effects. The authors believe that the main contribution of these trials so far, confirmed by other groups, is in examining prognostic features in al patients and finding that age and the presence of the Ph chromosome, independent of WBC count, gender, and cell type, is the main feature for predicting outcome. The UKALL XII trial will provide valuable information on the relative merits of transplantation and molecular studies of MRD. An in-depth study of a large number of Ph chromosome-positive ALL leukemias will also provide information on which to base future studies. Preliminary data suggest that all Ph-positive patients should undergo some sort of allograft early after CR is achieved, because these patients are not rescued by BMT after relapse. At the time of the publication of this article, preliminary studies suggest that STIs may not be as effective in Ph-positive ALL as in chronic granulocytic leukemia. The challenge for the future is to understand the biologic role of age and its impact on outcome so as to overcome "ageism" in adult ALL.