Cyclooxygenase-2 expression in endometrial polyps during menopause.

Objective: To determine whether cyclooxygenase-2 (COX-2) is expressed in endometrial polyps during menopause and how previous hormone use may affect this expression.

Patients And Methods: Fifty-two postmenopausal patients with endometrial polyps were enrolled for this study. Eighteen patients had no history of previous hormone use, while the remaining patients had used vaginal conjugated estrogens for short periods of time (n = 25) or were long-term users of tibolone (n = 5) or tamoxifen (n = 4). The endometrial polyps were removed by hysteroscopy, and COX-2 and Ki-67 expression were measured in tissue samples by immunohistochemistry.

Results: Endometrial polyps expressed COX-2 in the glandular epithelium and this expression was not significantly greater in patients who had previously used tibolone, tamoxifen or vaginal estrogens. However, Ki-67 expression was greater in the group using vaginal estrogens compared with the group of non-users; while in the other two treatment groups Ki-67 expression was less than in hormone never-users.

Conclusion: COX-2 expression is present in endometrial polyps during menopause and may play a role in their growth regulation.