Showing papers in "The Journal of Pathology and Bacteriology in 1936"

The effect of œstrone administration on the mammary glands of male mice of two strains differing greatly in their susceptibility to spontaneous mammary carcinoma

Abstract: Large doses (300-500 IU) of estrone (ketohydroxy-estrin benzoate) were administered subcutaneously in 187 male mice (79 of cancer-susceptible strain A 108 of cancer-resistant strain B) for periods ranging from 8-82 weeks. In the cancer resistant-strain mice growth and branching of the ducts occurred within a few weeks of treatment followed by accumulation of secretion which is eosinophil and of albuminous character. There was widespread proliferation of acini and cystic distention of ducts. No precancerous changes within the ducts were seen. In some of the mice there was considerable degree of periduct fibrosis. In the cancer-susceptible mice ductile growth and branching as well as acini proliferation also occurred. Acinar proliferation occurred after 43 weeks of estrone treatment. In 3 mice which developed mammary carcinomas at 43 47 and 53 weeks respectively all in regions other than the right inguinal groups of proliferating acini and distended ducts were seen at the edge of the tumor; the tumors were multiple in 2 and single in 1. It is believed that localized acinar proliferation is of more significance than cystic duct distention in the subsequent development of cancer in these mice. The findings suggest that similar experiments should use mice only of known ancestry.