Relevance of Mutagenesis to Carcinogenesis.

The development of a strong correlation between mutagenic agents and carcinogenic compounds is a direct consequence of the ability to determine both effects in mammalian systems. Prior to the development of mammalian tests for mutagenicity, mutagenic agents were evaluated for carcinogenicity in rodents. The major exceptions that were previously found for carcinogens not being mutagenic have been for the most part resolved by the use of rodents for testing both types of activity. Carcinogenic compounds such as cycasin and nitrosamines, which are not mutagenic when tested directly on bacteria, are now known to be mutagenic as well as carcinogenic. Procedures such as the host-mediated assay have contributed greatly to the establishment of a qualitative correlation between carcinogenic and mutagenic compounds. The use of available mammalian tests for mutagenicity should identify carcinogenic compounds in a fraction of the time needed for the conventional carcinogenic assay.