Mutagenicity--relevance of short-term tests.

Short-term tests measuring diverse biological activities of compounds, such as mutagenicity, have been proposed as prescreening methods to determine potential carcinogenicity. High correlations of up to 90% have been found for response in short-term tests versus response in long-term carcinogenicity assays, e.g. for the Salmonella-microsome method developed by Ames and also for the cell transformation test developed by Styles. How these short-term assays may be suited to predict potential carcinogenicity of N-nitrosamines is described. Data on how the mutagenicity of N-nitrosamines in the Salmonella-microsome assay compares to their carcinogenicity shows that correlation factors as high as 90% have not necessarily been obtained. The reasons for this apparent lack of correlation as well as which valuable role the short-term assays play in other fields of chemical carcinogenesis is discussed.