title: Radioisotope-decay model of carcinogenesis: multistep process in the formation of original single tumor cells induced by 3-methylcholanthrene in mice.
abstract: The times of origin of fibrosarcomas induced with 3-methylcholanthrene in mice were analyzed mathematically. Histograms of the rates of formation of original single tumor cells plotted against the time after carcinogen treatment fitted a two-step exponential decay function. This model was named a radioisotope-decay model by analogy with the multistep decay of radioisotopes. The half-lives of the initial and intermediate transient states were determined for three tumor groups, and were found to be 23-29 days for both states. The present study indicates the involvement of at least two steps in the establishment of tumors, even with a complete carcinogen.
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic; D005354:Fibrosarcoma / Q000139:chemically induced; D008433:Mathematics; D008748:Methylcholanthrene; D051379:Mice; D008809:Mice, Inbred C3H; D008813:Mice, Inbred ICR; D008954:Models, Biological
chemical_list: D008748:Methylcholanthrene