Mammary Cancer and Mammary Structure in Inbred Stocks of Mice and Their Hybrids

Abstract

Reciprocal matings were made between mice of cancerous A and C3H stocks and the virgin [female] hybrids were studied for incidence of mammary cancer and for mammary gland architecture by the whole mount technique. Virgin A [female][female] developed very few mammary tumors compared with C3H stock although the mammary glands were as well developed. This may result from differences in estrogen production to which the mammary glands react. The inherited estrogenic influence is transmitted as a dominant. This influence is probably not identical with the inherited susceptibility for spontaneous mammary cancer. Precancerous nodules probably result from combined action of estrogenic hormones and the mammary tumor milk agent.