Can the concept of hormesis be generalized to carcinogenesis?

The concept of hormesis (i.e., few-dose stimulation/high dose inhibition) h as been shown to be widely generalizable with respect to chemical class, an imal model, gender, and biological end point. The public health implication of this lack of linearity in the low-dose area of the dose-response curve raises the question of whether low doses of carcinogens will reduce cancer risk. Articles relating to the process of carcinogenesis (i.e., initiation, promotion, tumor development, and progression) were obtained from a recent ly developed chemical hormesis database and evaluated for their evidence of hormesis. Numerous examples in web-designed studies indicate that U- or J- shaped dose-response relationships exist with respect to various biomarkers of carcinogenesis in different animal models of both sexes. Examples of su ch J-shaped dose-response relationships in each stage of the process of car cinogenesis were selected for detailed toxicological examination. These res ults have important implications for both the hazard assessment of carcinog ens and cancer risk assessment procedures. (C) 1998 Academic Press.