Interspecies Concordance for Chemicals with Anti-Carcinogenic Activity. George M. Gray, Harvard Center for Risk Analysis, Harvard School of Public Health, 718 Huntington Avenue, Boston, MA 02115; and Ping Li and Richard Wilson, Department of Physics, Harvard University, Jefferson Laboratories, Cambridge, MA 02138
We have used 317 chemicals in the CBDS data base (National Toxicology Program) to study the apparent anti-carcinogenic properties of chemicals. Because of obvious statistical problems, we can only detect anti-carcinogenic activity with common tumors (with higher background rate). The number of chemicals observed having anti-carcinogenic property goes up almost linearly as the background rate increases. Of the chemicals inducing common tumors, there is a 90% concordance between the anti-carcinogenic potential in one rodent species and in another. This is greater than the 80% concordance found for ordinary carcinogenic activity. Of the 155 chemicals showing carcinogenic activity in both mouse and rat, half of them also shown anti-carcinogenic activity in both of the species. The data will be presented and the implications will be discussed.