INHIBITION OF MAMMARY-CANCER BY RETINYL METHYL-ETHER

Abstract

Daily feeding of the synthetic retinoid, retinyl methyl ether, beginning 1 wk after the oral administration of 7,12-dimethylbenz(a)anthracene to female Sprague-Dawley rats, inhibited the incidence of mammary cancer and diminished the number of mammary tumors, malignant and benign, caused by 7,12-dimethylbenz(a)anthracene. Retinyl methyl ether also increased the latent period for appearance of mammary cancers. Retinyl methyl ether caused no evident toxicity and did not affect weight gain in these experiments. This synthetic retinoid was superior to the natural retinoid, retinyl acetate, for inhibition of mammary carcinogenesis.