Initiation and promotion in radiation-induced myeloid leukemia

Acute myelomonocytic leukemia develops in 10-80% of irradiated (800 rad) SJL/J mice, after a lag period of around one year. Additional treatment with dexamethasone shortly after irradiation increased leukemia incidence up to 50%. Experiments were conducted in order to demonstrate the existence of preleukemic cells in irradiated mice and to explore the possible role of dexamethasone, cyclophosphamide, and different hemopoletic growth factors on their promotion to overt leukemia