Expression of Bcl-2 and Ki-67 in Tamoxifen-Associated Endometrial Polyps: Comparison with Postmenopausal Polyps

Abstract

Background: The aim of this study was to evaluate the expression of Bcl-2 and Ki-67 in tamoxifen (TAM)-associated endometrial polyps and postmenopausal polyps. Material and Methods: For this purpose, a retrospective analysis of paraffin-embedded specimens was carried out. Polyps of 20 postmenopausal and 14 TAM-treated patients, 11 simple endometrial hyperplasia, 10 atypical complex endometrial hyperplasia and 8 endometrial adenocarcinoma specimens were included in the study. Hematoxylin/eosin-stained sections were evaluated. Immunohistochemical staining was performed to investigate the expression of Bcl-2 protein and the Ki-67 proliferation index. Results: There was no statistically significant difference between the 5 groups with regard to Bcl- 2 staining (p > 0.05). However, Bcl-2 expression in TAM-associated polyps was higher (86%) than in the postmenopausal control group (80%). Positive Ki-67 was highest in the endometrial adenocarcinoma specimens, followed by the atypical complex endometrial hyperplasia group (p < 0.0001). Compared to these 2 groups, Ki- 67 expression was lower in TAM-associated polyps, but Ki-67 indexes were significantly higher in the TAM-associated group than in the control group (p < 0.0001). Conclusion: Since TAM-associated polyps tend to have higher proliferation indexes and Ki-67 ratios than control groups, we suggest that they are likely to have a higher malignant potential.

Endometrial polyps: Pathogenesis, sequelae and treatment

“…17 Other studies have similarly observed that there is decreased apoptosis in endometrial polyp tissue. [18][19][20] Glandular, menopauseindependent AB DNA fragmentation factor 40, 45 (DFF40), (DFF45) and Bcl-2 overexpression may play an important role in the pathogenesis of endometrial polyps. 21 Ki67 expression was observed to occur predominately in the proliferative phase, with glandular epithelium exhibiting the strongest expression.…”

Expression of apoptosis-related genes in the endometrium of polycystic ovary syndrome patients during the window of implantation

“…Bcl-2 expression is higher in the endometrium of PCOS patients than in a control group. Bcl-2 expression also forms more heterodimers by binding to BAX to inhibit the apoptosis of PCOS endometrial cells (Altaner et al, 2006;Tao et al, 1997). During a regular menstrual cycle, Bcl-2 expression is regulated by sex hormones.…”

Tumorigenic Effects of Tamoxifen on the Female Genital Tract

“…There is patchy condensation of the stromal cells around the glands. It has been reported that Bcl-2 and Ki-67 expression was higher in tamoxifen-associated polyps than in postmenopausal untreated polyps (Altaner et al 2006). These findings suggest that tamoxifen-associated endometrial polyps have higher rates of cell mitotic activity and apoptosis inhibition; these higher rates may play a crucial role in the malignant transformation of such endometrial polyps.…”