EFFECTS OF TAMOXIFEN AND OVARIECTOMY ON THE ENDOMETRIUM OF THE UTERUS OF ADULT ALBINO RAT Hafiz Waly Ahmed*, Medhat M. Morsy*,Hanan Dawood Yassa** and Samira Maher Youssef** Anatomy and Embryology Department, Faculty of Medicine, Cairo University* and Beni-Suif University**
Background: The actual concepts of therapeutic strategy for breast cancer have included two major lines of treatment; the first line is the use of anti-hormonal therapy especially in patients whose tumors are estrogen receptor positive. The second line of choice is the surgical ablation of the ovaries by performing ovariectomy. Aim of work: This study was designed to study and compare the effect of the two major lines of treatment of cancer breast; which are anti-hormonal therapy, tamoxifen administration, and ovariectomy on the endometrium of the adult albino rat. Material and Methods: Seventy adult female albino rats weighing 150-200g were used and classified into four groups, I - Control Group, II- Sham Group (a: sham for tamoxifen, b: sham for ovariectomy), III-Treated Group (three subgroups; a, b, c, received 0.4, 1 or 10 mg/kg of tamoxifen respectively by oral gavage daily for one month) and IV- Bilaterally Ovariectomized Group. At the end of the experiment; thirty days, vaginal smear was done daily at a fixed time of the day to detect the phase of estrous cycle. The diestrus phase was selected at the time of scarification. The uteri were prepared for light microscopic and morphometric studies using. Hx.&E and Masson's trichrome stains. Results: The present work demonstrated that, both tamoxifen and ovariectomy produced variable histopathological changes in the uteri of the rats. For tamoxifen subgroups, the uteri showed hyperplasia and hypertrophy of the endometrial lining epithelium with apoptotic changes. The endometrial glands also showed hyperplastic lining epithelium, dilated lumina and budding in some of them. Extravasated blood and cellular infiltrations were also observed. The severity of these changes was dose dependant. On the other hand, the uteri of the ovariectomized rats revealed atrophy of both of the endometrial glands and the lining epithelium. Conclusion: Both tamoxifen administration and ovariectomy induced marked effects on the endometrium. Tamoxifen induced hyperplasic changes that might be carcinogenic especially in high doses, while atrophic changes were prominent after ovariectomy. Therefore, the decision of bilateral ovariectomy is safer for the uterus than using high doses of tamoxifen for treatment of estrogen responsive cancer breast. However, appropriate benefit/ risk assessment is highly recommended to precisely choose the right decision.
June 2012