Hormonal Influences on the Growth of a Transplantable Mammary Adenocarcinoma in C3H Mice23

Abstract

Propylthiouracil administration produced a marked body weight loss in C3H mice and a significant depression of the growth rate of the DRV mammary adenocarcinoma in these hosts. An equal degree of inanition attained by dietary restriction produced comparable tumor growth suppression. Mice made hypothyroid by thyroid-lethal doses of radioactive iodine did not lose weight and the tumor growth rate was unaffected in such hosts. The DRV mammary tumor grew equally well in intact males and intact females and more rapidly in castrate than in intact mice of either sex. The administration of a nontoxic dose of diethylstilbestrol to castrated female mice decreased the rate of growth of the tumor, while the administration of prolactin to ovariectomized diethylstilbestrol-treated females enhanced tumor growth. However, lactation per se did not influence the growth rate of the tumor. Although the DRV tumor appears to be responsive to one or more pituitary hormones, it does not appear to be hormone dependent since it grew progressively in hypophysectomized hosts.