BACKGROUND: Early response to therapy is defined as the initial response prior to Day 28 of treatment, the conventional time of marrow evaluation. The number of reports linking early response to therapy with the ultimate outcome of childhood @entity981 is substantial and growing. When this study began, these experiences had yet to be comprehensively reviewed. METHODS: A comprehensive search of the published literature yielded contributory reports of 14 trials conducted in the United States and Europe. In addition, unpublished data from one @entity1 's Cancer Group trial were made available. Outcome measures were standardized by conversion to ratios of the incidence of adverse events among poorer and better responders. RESULTS: Early response to therapy was an independent prognostic factor in each of the 15 trials, which together included more than 10,000 @entity1 . The incidence of slower early response ranged from 2-33%, with various measures and criteria used in different trials. @entity1 with a slower early response were 1.5-6.1 times (median, 2.7) more likely to have an adverse event than @entity1 with a more rapid early response, however defined. Early response maintained prognostic significance after the exclusion of induction failure and within risk strata defined by age, white blood cell count, and/or immunophenotype. Its significance was also maintained in multivariate analyses where performed. CONCLUSIONS: Early response to therapy, whether determined by evaluation of bone marrow or peripheral blood, is a consistent, independent prognostic factor in childhood @entity981 . Slower early response may serve as a useful surrogate for outcome, a more complex end point, in investigations of the cellular and molecular determinants of resistance to therapy. It may also allow early identification of a @entity1 subpopulation for whom current therapy is less effective and alternative strategies may be justified.

Early response to therapy and outcome in childhood XXXX : a review.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients', 'Children', 'patient'] @entity981 :: ('MESH:D054198', 'Disease') :: ['acute lymphoblastic leukemia']
@entity981 :: (MESH:D054198,Disease) :: ['acute lymphoblastic leukemia']
