Increased incidence of carcinoma of the breast in Buffalo strain rats with one kidney ingesting N-4-(4'-fluorobiphenyl)acetamide.

The role of the kidney in carcinogenesis of the breast was studied in inbred Buffalo strain female rats ingesting 0.04% N-4-(4'-fluorobiphenyl)acetamide. The experimental groups consisted of intact female rats 5 weeks of age with both kidneys intact and female rats with a uninephrectomy. The incidence of carcinomas of the breast and the number of rats with multiple carcinomas, poorly and undifferentiated carcinomas was greater in rats with a uninephrectomy. N-4-(4'-fluorobiphenyl)acetamide and its active metabolites apparently were not excreted as rapidly in the rats with one kidney as in the animals with both kidneys intact. The metabolites were then returned to the breast and/or other organs.