Detection of Interactive Effects in Carcinogenesis

The multistage theory for cancer is used to derive models for independent effects and for interactive effects of two carcinogenic agents. The derivation assumes that a tumor is of single cell origin and that a normal cell is transformed to a cancer cell by undergoing a finite number of irreversible, heritable, mutation‐like transitions. The interactions enter the proposed models at the level of single cell transition rates rather than, as is conventional, at the level of animal response proportions. Suggestions are given for the design and analysis of fixed time, binary response, two factor, cancer bioassay experiments.