The aim of the present study was to evaluate estrogen receptor (ER) and progesterone receptor (PR) expression in the glandular epithelium and stroma of benign and malignant endometrial polyps of postmenopausal patients. A total of 1,050 females underwent surgical hysteroscopy at the Professor Dr José Aristodemo Pinotti Women’s Hospital, Center for Integral Attention to Women’s Health of the State University of Campinas, between January 1998 and December 2008. Of the total number, 390 postmenopausal females with endometrial polyps were included in the study. Polypoid lesions were histologically classified as benign lesions (endometrial polyps and polyps with non-atypical simple hyperplasia or non-atypical complex hyperplasia) and premalignant and malignant lesions (polyps with atypical simple hyperplasia or atypical complex hyperplasia and carcinomatous polyps). ER and PR expression was evaluated by immunohistochemistry according to cell staining, intensity of nuclear staining and final score. The final score for receptor expression was compared between the benign and premalignant/malignant polyps. The prevalence of malignancy in endometrial polyps was 7.1% and was associated with postmenopausal bleeding. Only the final score for ER expression in the stroma of endometrial polyps was higher in the benign group than in the premalignant/malignant group, and this difference was significant. However, no difference was identified in PR expression. In addition, the risk of malignancy in endometrial polyps was significantly higher when the expression of ER and PR was negative in the stromal component of the polyp (P<0.01). The malignancy of endometrial polyps was also associated with a low expression of stromal ER, however, PR expression did not show any association with the risk of malignancy.

Abstract.Postmenopausal women who use tamoxifen present with an increased incidence of endometrial alterations, such as polyps and hyperplasia, in addition to a higher risk of malignant endometrial neoplasms. Among these endometrial changes, polyps are the most common, with a pathogenesis associated with hormonal influence. The objective of this study was to compare the expression of estrogen receptors (ERs) and progesterone receptors (PRs) in endometrial polyps from tamoxifen users with that in endometrial polyps and the atrophic endometrium of postmenopausal tamoxifen non-users. Among women undergoing surgical hysteroscopy, 84 tamoxifen users with benign endometrial polyps were selected. This group was compared to 84 samples of atrophic endometrium and to 252 benign polyps from postmenopausal women who were not treated with tamoxifen. The expression of ER̸PR was assessed by immunohistochemical analysis, according to the percentage of stained cells, intensity of nuclear staining and final score. The polyps from tamoxifen users exhibited a higher expression of ER and PR in the glandular epithelium and stroma compared to the atrophic endometrium (P<0.0001). Compared to the polyps from women not treated with tamoxifen, tamoxifen users exhibited a higher PR expression in the epithelium (P=0.0014) and stroma (P=0.0056), with no difference in the expression of ER. In conclusion, endometrial polyps frequently exhibit an increase in ER expression, regardless of tamoxifen use. High levels of PR expression appear to be consistent with the estrogen agonist effects of tamoxifen.

No abstract

No abstract

No abstract