Discontinuing therapy in childhood acute lymphocytic leukemia. A multicentric survey in Italy.

The results of discontinuing therapy in children with acute lymphocytic leukemia observed at four associated institutions are presented. Of the 247 patients who achieved complete remission, 122 (49.3%) reached the point of discontinuing therapy after 2-4 years of continuous remission. The median period off therapy was 13 months with a range of 1-69 months. Of the 122 children removed from therapy, 27 (22.1%) relapsed, mainly in the bone marrow; relapses occurred 1-32 months after cessation of therapy (median ten months) with only two relapses occurring later than two years. By actuarial analysis, 57% of the patients are projected in continuous remission after five years from cessation of therapy. Neither selected features at diagnosis nor single modalities of treatment were found to predict whether relapse would occur after discontinuing therapy. Long-term remission and possibly cure can be expected in over one-third of newly diagnosed children with ALL after 2-4 years of antileukemic treatment.