Blast cells in acute myeloblastic leukemia: a model

A model of the evolution of acute myeloblastic leukemia (AML) as a clonal hemopathy is presented and reviewed in light of the available data on the behavior of leukemic blast-stem cell colonies. The model postulates that determination of a pluripotent stem cell of a leukemic clone occurs abruptly with intermediate stem cell classes being rare. Transformations occurring in committed myelopoietic progenitors are not self-maintaining. Leukemic clones in AML originate by genetic transformation to a lineage independent of myelopoietic differentiation. The biological behavior of AML clones changes with time as a result, in the short term, of environmental changes, and in the long term, of genetic changes. Sensitivity of leukemic blast colonies to adriamycin and Ara-C, although variable from patient to patient, is relatively stable for one clone during a major portion of the course of the disease.