Incidence of Spontaneous Mammary Tumors in Mice with Lithospermum- Induced Diestrus.

Abstract

About 400 6-month-old virgin female C3H mice were divided into two groups: one was maintained on a normal diet; the other on an anti-estrous diet of 10-15% Lithospermum. Eighteen months later the latter group had developed half as many spontaneous mammary tumors as the former; however, if the differential mortality observed throughout the experiment is taken into statistical account, the tumor incidence ratio for the total period is 3 for the control, 2 for the experimental group. This reduction in tumor incidence was possibly connected with the Lithospermum-diestrus, but inanition and differential survival factors remain to be more fully evaluated.