Myelodysplastic syndromes in childhood: description of seven cases
Banded chromosome studies obtained at the time of diagnosis from 42 patients with the preleukemic syndrome had clonal abnormalities in fifteen. Using Kaplan-Meier product limit survival analysis, it was found that patients with chromosome abnormalities developed acute leukemia more frequently than those without (p less than 0.05). However, we noted that in a subset of patients with complex abnormalities and in a subset previously exposed to alkylating agents, almost all developed leukemia. When either subset was excluded from the larger group analysis there were no differences in leukemia-free survival between cytogenetically abnormal and normal groups. Thus, in the prognostic evaluation of our patients with the preleukemic syndrome a chromosome abnormality per se did not predict rapid evolution to acute leukemia. However, almost all preleukemic patients with complex chromosome abnormalities and almost all alkylator-exposed preleukemic patients can be expected to develop overt leukemia within 1 yr.