Occurrence of Tumors in Agent-Free Strain C3H f Male Mice Implanted with Estrogen-Cholesterol Pellets

Abstract

Summary

1. Mammary tumors occurred in 12 or 20% of 60 agent-free strain C3H_f male mice implanted with pellets of cholesterol containing 10% of diethylstilbestrol. The average age at which the tumor arose was 15.1 months. Tests of cell-free filtrates of 5 of these tumors selected at random failed to give evidence of the presence of the mammary tumor agent. 2. Hepatomas occurred in 14 or 23% of the diethylstilbestrol-treated males at an average age of 22.6 months. This incidence is significantly less than that recorded for untreated strain C3H_f males of a comparable age, but greater than that recorded for untreated C3H_f females of comparable age.