Carcinogenicity of captafol in B6C3F1 mice.

The potential carcinogenicity of captafol in B6C3F1 mice was examined. Captafol was given at levels of 0 (control), 0.075, 0.15 or 0.3% in the diet to a total of 203 males and 203 females for 96 weeks, after which time the animals were returned to basal diet for a further 8 weeks. Mice surviving 42 weeks or longer were included in the effective numbers. Males and females given 0.3% captafol showed increased cumulative mortalities in the final quarter period of the experiment. Significant increases in the development of neoplastic lesions were found in the heart, spleen, forestomach, small intestine and liver of mice of both sexes treated with captafol. Tumors induced by captafol were, histologically, hemangioendothelioma in the heart, hemangioma or hemangioendothelioma in the spleen, papilloma and squamous cell carcinoma in the forestomach, adenoma and adenocarcinoma in the small intestine, and hyperplastic nodule and hepatocellular carcinoma in the liver. These results demonstrate a broad-spectrum carcinogenicity of captafol in B6C3F1 mice.