European Journal of Gynaecological Oncology (EJGO) is published by IMR Press from Volume 40 Issue 1 (2019). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with S.O.G.
Expression of estrogen receptors α and β in two uterine mesenchymal tumors after prolonged tamoxif en therapy. Report of two cases
Introduction: Tamoxifen therapy is associated with an increased risk of endometrial carcinoma, and possibly uterine sarcomas. Little is known about hormone receptor expression in mesenchymal tumors of the uterus after tamoxifen therapy. Cases: The cases of two patients with uterine mesenchymal tumors after prolonged tamoxifen therapy due to breast cancer are presented. The expression of estrogen receptors alpha (ERα) and beta (ERβ) and progesterone receptors (PR) was studied immunohistochemically in both cases. Both tumors were negative for ERα and positive for ERβ. In the first case the tumor was negative for PR, while in the second only 20% of nuclei were PR-positive. Conclusions: Consistent with previous studies, uterine mesenchymal tumors after tamoxifen therapy do not express ERα. The results of the present report provide for the first time evidence that tamoxifen might exert a stimulatory effect on the uterus, at least during tumor progression, through ERβ but not through ERα.