The micronucleus test as part of a short-term mutagenicity test program for the prediction of carcinogenicity evaluated by 143 agents tested.

To evaluate the usefulness of the micronucleus test as a short-term assay for the detection of carcinogens, the correlation between micronucleus test data for 143 chemicals and corresponding cancer data, has been analyzed. For comparison, analogous data from Ames's test have also been collected for the same chemicals. In a comparison of the micronucleus test and Ames's test it was found that they had about the same specificity (around 80%) and predictive value (around 90%), while there was a significant difference in sensitivity in favor of Ames's test. The difference in sensitivity could be partly explained by differences in metabolizing capacities of these two test systems. It is concluded that a more elaborate test procedure for the micronucleus test would increase that sensitivity of this test. The principal value of the micronucleus test lies in the fact that it is an in vivo method, which may pick up effects at the chromosomal level not covered by bacterial assays. This is emphasized by the finding that the combination of Ames's test and the micronucleus test did increase the sensitivity of the screening procedure for the prediction of carcinogenic effects.