Effect of Testosterone Propionate on Development and Growth of Mammary Carcinoma in Female Mice.

Abstract

Estrogen, when administered to male mice of certain strains, will result in the appearance of spontaneous mammary carcinoma., , The females of these strains ordinarily have a high incidence of spontaneous mammary carcinomas, which do not normally occur in the males. It has further been demonstrated that the incidence can be increased and the time of appearance of the mammary carcinoma hastened by the administration of estrogen to the females of these same strains. Recently, Lacassagne tested the effect of testosterone upon development of mammary carcinoma in females of a high incidence strain and noted no alteration from the controls. The dosages used, however, were small. It is the purpose of this communication to report the results of long term injections of testosterone propionate upon subsequent development and growth of spontaneous mammary tumors in female mice with an extremely high incidence (95%). Forty female mice of the C3H strain, born at approximately the same time, were kept under similar experimental conditions. They were then bred at maturity and all except 2 animals had their litters within several weeks of each other. The remaining 2 animals had litters one month after the first of the entire group. The litters were killed within 24 hours after birth and the animals were then divided into 2 groups of 20. For every animal in one group, there was a sister litter mate in the other. At the age of 4 1/2 months, injections of testosterone propionate in sesame oil were given to one group of 20, dosage 0.5 mg in 0.05 cc of oil 3 times weekly for a period of 4 months.