Histopathology of Breast Lesions Induced in BUF Rats of Varying Ages by Ingestion of N-4-(4'-Fluorobiphenyl)acetamide

Summary

Inbred BUF male and female rats 4, 12, 24, and 52 weeks old ingested 0.04% N-4-(4'-fluorobiphenyl)acetamide in a semisynthetic diet for 36 weeks. They were killed 12 weeks later. Susceptibility to mammary carcinogenesis was related to the age and sex of the animals. Younger female rats developed more mammary tumors. Approximately half of these mammary tumors were welldifferentiated adenocarcinomas; the remainder were either poorly differentiated or anaplastic adenocarcinomas.