Effect of Hormone Replacement Therapies and Dietary Phytoestrogens on the Mammary Gland of Macaques.
Annual rept. 1 Jul 94-30 Jun 95,
BOWMAN GRAY SCHOOL OF MEDICINE WINSTON-SALEM NC
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The purpose of this study was to use histomorphometric and immunohistochemical techniques to study the incidence and characteristics of mammary gland hyperplasia, dysplasia and other possible indicators of breast cancer risk, in cynomolgus macaques given long-term hormonal treatments. Treatments evaluated to date include conjugated estrogens CEE, medroxyprogesterone acetate MPA, the combination of CEE and MPA, tamoxifen, estradiol E2, and 17a-dihydroequilenin DHEN. Pathologic evaluation, histomorphometric evaluations, and staining for estrogen receptor, progesterone receptor, and the proliferation marker Ki-67 MIB were done. Results are as follows The addition of MPA to CEE therapy increases, rather than decreases, mammary gland proliferation. This finding is in contrast to the uterus, where MPA antagonizes the proliferation induced by CEE. Estrogen receptor expression in mammary gland epithelium is decreased by treatment with CEE, and further decreased by the addition of MPA. Progesterone receptor expression in mammary gland epithelium is increased by treatment with CEE, and decreased by the addition of MPA. Tamoxifen treatment does not induce mammary land proliferation beyond that seen in controls this is in contrast to a marked uterotrophic effect. DHEN does not induce mammary gland or endometrial proliferation, relative to controls and in contrast to E2.
- Medicine and Medical Research
- Anatomy and Physiology