Predictors of malignancy in endometrial polyps: study of 421 women with postmenopausal bleeding

Objective: There is lack of consensus as whether benign-looking endometrial polyps should be removed in postmenopausal women. To help inform clinical practice, this study was conducted to quantify the prevalence and identify the predictors of hyperplasia and cancer in polyps. Methods: The data of 2625 consecutive women attending a postmenopausal bleeding clinic were collected prospectively in a UK teaching hospital between January 2011 and December 2015. Of them, 421 (16%) women with hysteroscopically benign-looking endometrial polyps with normal background endometrium were included. Results: The number of women with benign polyps versus hyperplasia or cancer in polyps was 387 (92%) vs. 34 (8%). The risk of hyperplasia and cancer in polyps was 5.5-fold and 3.5-fold higher in women with endometrial thickness≥ 10.8 mm and in women with body mass index ≥ 32.5 kg/m², respectively. Age, years since last period, ethnicity, recurrent postmenopausal bleeding, diabetes, hypertension, and the use of tamoxifen did not differ between the outcome groups. Conclusion: The prevalence of hyperplasia and cancer in benign-looking polyps is high. The independent predictors are body mass index and endometrial thickness. Removal of polyps may be warranted until hysteroscopic morphological criteria that can reliably predict the outcome are established in future research.