The prognostic value of chromosome studies in patients with the preleukemic syndrome (hemopoietic dysplasia).

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.