Inhibition of carcinogen-induced neoplasia by sodium cyanate, tert-butyl isocyanate, and benzyl isothiocyanate administered subsequent to carcinogen exposure.

The effects of sodium cyanate, tert-butyl isocyanate, and benzyl isothiocyanate on carcinogen-induced neoplasia were studied in experiments in which the test compound was fed starting 1 week following completion of carcinogen administrations. Under these conditions, all three test compounds exerted an inhibitory effect on the occurrence of 7,12-dimethylbenz(a)anthracene-induced neoplasia of the breast of Sprague-Dawley rats. In a second experiment model, sodium cyanate inhibited the occurrence of 1,2-dimethylhydrazine-induced neoplasia of the large bowel of female CF-1 mice. Thus, a new group of compounds has been identified which has inhibitory capacities against neoplasia when given subsequent to carcinogen exposure.