New perspectives for alternative approaches to carcinogenicity testing: a regulator viewpoint

Genotoxic compounds are thought more likely to be transspecies carcinogens inducing carcinomas in more than one species, implying a hazard to humans. Non-genotoxic compounds will have a certain threshold concentration below w hich they are definitely not carcinogenic. What are we looking for in the c ase of pharmaceuticals? New animal models would be helpful to enhance the q uality of assessment of carcinogenic potential, based on 'weight of evidenc e', in order to reach the goal of replacing animal life span studies withou t compromising human safety. Such studies should supplement life span studi es and provide additional information not readily available from the long-t erm assay. Short- or medium-term assays may be helpful in confirming the tr ansspecies character of carcinogens. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.