This study was undertaken to investigate the expression of p53, Ki-67, and CD31 proteins in endometrial polyps of postmenopausal women treated with tamoxifen (TAM). Postmenopausal women with endometrial polyps treated with TAM (n = 20), postmenopausal women with endometrial polyps without hormone use (n = 20), postmenopausal women with atrophic endometrium (n = 20), and postmenopausal women with endometrial adenocarcinoma (n = 20) were prospectively investigated. Tissue samples were immunohistochemically evaluated by monoclonal antibodies for p53, Ki-67, and CD31. The data were analyzed using the Student t test, analysis of variance, and χ2 to evaluate significant differences between the groups. The level of significance was set at P < 0.05. There was no difference in the expression of p53 between the groups (P = 0.067). The expression of Ki-67 was higher in the polyp samples from TAM-treated women compared with those from the women using no hormone (P = 0.0047) and those from the women with atrophic endometrium (P = 0.008). Samples from the women with endometrial cancer was associated with higher Ki-67 expression compared with the polyp samples from TAM-treated women (P = 0.004). The expression of CD31 was higher in the polyp samples of TAM-treated women compared with that of the samples from the women with atrophic endometrium (P < 0.001) and similar to the polyp samples from the women using no hormone (P = 0.319) and to the samples from the women with endometrial cancer (P = 0.418). The use of TAM in postmenopausal women might be associated with increased cellular proliferation in endometrial polyps without interfering angiogenesis or inactivation of tumor suppressor proteins.
*Department of Gynecology and Obstetrics, Botucatu Medical School, São Paulo State University, Botucatu, São Paulo, Brazil; Departments of †Obstetrics and Gynecology, and ‡Pathology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Received March 18, 2009, and in revised form July 22, 2010.
Accepted for publication August 16, 2010.
Address correspondence and reprint requests to Agnaldo Lopes da Silva Filho, MD, PhD, Department of Obstetrics and Gynecology, Federal University of Minas Gerais (UFMG), Avenida Professor Alfredo Balena 190, Santa Efigênia, Belo Horizonte, MG, Brazil 30130100. E-mail: firstname.lastname@example.org.