Radiation-induced acute myeloid leukemia in the mouse: experimental observations in vivo with implications for hypotheses about the basis of carcinogenesis.

Acute myeloid leukaemia induction by X- and gamma-rays in 4 mouse strains follows the same dose-response aD2e-lambda D. The (dose)2 interaction disappears within 3 days. AML appears earlier when syngeneic marrow cells are injected 3 days after irradiation, minimum latent period and final frequency remaining unchanged. Dose-responses for brief and protracted exposures are quite different for non-myeloid 'leukemia'. The results seem incompatible with a common model for initiation of both leukaemia categories and with orthodox concepts that initiation is a stable state and must be followed by multiple events over a period of time before cells express fully malignant behaviour.