Regression and persistence of hyperplastic hepatic nodules induced by N-2-Fluorenylacetamide and their relationship to hepatocarcinogenesis.

A dietary regimen containing the carcinogen N-2@fluorenyl acetamide for the induction of hyperplastic hepatic nodules and hepatocellular carcinomas is presented. Administration of the carcinogen for 3 months yields a high number of nodules that regress after withdrawal of the carcinogen, and the in@ cidence of hepatocellular carcinomas is very low. Feeding of the carcinogen for 1 additional month yields a population of nodules that persist after withdrawal of the carcinogen and are associated with a high incidence of hepatocellular carcinomas. This regimen may aid in the delineation of characteristics of nodules relevant to malignant transformation.