Is the immunohistochemical expression of proliferation (Ki-67) and apoptosis (Bcl-2) markers and cyclooxigenase-2 (COX-2) related to carcinogenesis in postmenopausal endometrial polyps?

OBJECTIVE

To evaluate the pattern of Ki-67, Bcl-2 and COX-2 expression in the glandular epithelium and stroma of malignant and benign endometrial polyps in postmenopause.

STUDY

DESIGN

A total of 390 postmenopausal women underwent surgical hysteroscopy; women with endometrial polyps were included. Polypoid lesions were histologically classified as benign, premalignant or malignant lesions. Ki-67, Bcl-2 and COX-2 expression were evaluated by immunohistochemistry according to percentage of stained cells, staining intensity, and final score.

RESULTS

The prevalence of malignancy in endometrial polyps was 7.1% and was associated with postmenopausal bleeding. The final score showed that only mean COX-2 expression was higher in malignant polyps both in the glandular epithelium (6.1 +/- 2.5) (p < 0.001) and stroma (2.4 +/- 3.0) (p < 0.01). There was a higher Bcl-2 expression, especially in the glandular epithelium, with no differences between benign polyps and premalignant/malignant polyps. Ki-67 expression was low in both benign polyps and premalignant/malignant polyps.

CONCLUSION

Polyps in postmenopause have a high COX-2 expression that is higher in malignant polyps than in benign polyps. There was no difference in Ki-67 and Bcl-2 expression between malignant polyps and premalignant/malignant polyps.