Mouse strains for chemical carcinogenicity studies: overview of a workshop.

Chemical toxicology and carcinogenesis are dynamic disciplines, and the methodologies associated with these evaluations are under constant development and change. Accordingly, early in 1983, at the request of the National Toxicology Program (NTP), the NTP Board of Scientific Counselors established an Ad Hoc Panel on Chemical Carcinogenesis Testing and Evaluation with Dr. John Doull (University of Kansas) as the chairman. The charge to this Panel was to review the basic biology and chemistry of chemical carcinogenesis and to recommend to the NTP Board of Scientific Counselors methods that the NTP should use for the detection and evaluation of chemical carcinogens. The Panel issued a report (NTP, 1984) with a number of recommendations, one of which was “If a determination is made to maintain a two species bioassay protocol, give serious consideration to replacement of the B6C3Fl mouse with a strain having an established lower and less variable spontane-