Efficacy of estriol in inhibiting epithelial proliferation in mammary fibroadenoma: randomized clinical trial

Abstract

CONTEXT AND OBJECTIVE: Mammary fibroadenoma is a disease that affects a large number of women of reproductive age. The aim of this study was to evaluate the proliferative activity of mammary fibroadenoma through expression of Ki-67 and c-myc antigens, following administration of oral contraceptive with or without estriol. DESIGN AND SETTING: Placebo-controlled double-blind randomized clinical trial in the Mastology Sector of the Department of Gynecology, Universidade Federal de São Paulo. METHODS: Thirty-three fibroadenoma patients were studied. Ten women (group 1) took an oral contraceptive constituted by levonorgestrel and ethinyl estradiol together with placebo manufactured in the same capsule for four consecutive cycles with a seven-day interval between them. The other 23 patients (group 2) took the same oral contraceptive together with estriol, which was put into the same capsule and used in the same way as among the group 1 patients. After four cycles, the nodules were surgically removed and sent for immunohistochemical analysis of Ki-67 and c-myc expression. RESULTS: The Ki-67 and c-myc analysis did not reveal any significant differences between the study groups. The values were 9.16 and 10.54 for group 1 and 10.86 and 17.03 for group 2, respectively. There was a tendency towards higher expression of antigens in group 2. CONCLUSION: Our results showed that there was no significant statistical difference in Ki-67 and c-myc expression between our study groups, but only a tendency towards higher expression among users of oral contraceptives containing estriol.

Wnt pathway is affected by endocrine therapy in breast carcinomas

“…We may infer from these results that tamoxifen treatment somehow attenuates c‐myc expression. On the contrary, in a recent study by our group, 42 estradiol, administered as contraceptive pills to patients with mammary fibroadenoma, did not affect c‐myc expression. However, c‐myc is considered a downstream effector of the Wnt pathway and can also activate the Wnt pathway in a positive feedback loop that is still being studied 37 .…”

xpression of estrogen and progesterone receptor genes in endometrium, myometrium and vagina of postmenopausal women treated with estriol

“…[14][15][16][17] The data so far available concerning estriol action on the endometrium, myometrium, vagina and breast are ambiguous, and they provide contradictory information. [18][19][20][21] It seems that differences in the affinity, specificity and concentrations of ERs in individual tissues are of much greater importance, together with changes in effector tissues that lead to different responses.…”