Risks of Malignancy among 11,204 Patients with Endometrial Polyp: A Systematic Review and Meta-analysis

Abstract

Objectives: To evaluate factors associated with malignancy in patients with endometrial polyps. Materials and Methods: We conducted electronic database research on PubMed, MEDLINE, EMBASE, COCHRANE, and Google Scholar from inception for all studies on endometrial polyp. After removing duplicates, and title and abstract screening, we had a total of 121 articles and 151 others from screening the reference list. Inclusion criteria included peri and postmenopausal women > 45 years diagnosed histopathologically with endometrial polyp(s). We excluded women with a history of endometrial cancer or hysterectomy. Results: Twenty studies were analyzed. Of 11204 patients with endometrial polyp, 287 had malignant polyps (2.75%), 182 (1.8%) had concomitant endometrial hyperplasia with atypia, and 520 (5.2%) had hyperplasia without atypia within the polyp. Menopausal women had a higher risk of pre-malignancy/malignancy than non-menopausal women (OR 5.63 (95CI 3.87, 8.20, I 2 = 0%, P < 0.001). Endometrial thickness on ultrasound in pre-malignancy/malignancy cases was significantly thicker than in the benign polyp (mean difference 4.2 mm, 95% CI 0.8 to 7.6 mm, I 2 = 18%, P = 0.02). Women who used tamoxifen or hormone replacement therapy (HRT) had a lower likelihood of endometrial pre-malignancy/malignancy, while women with abnormal uterine bleeding (AUB) had a higher probability of pre-malignancy/malignancy. The odd ratio of having pre-malignancy/malignancy among those who used tamoxifen was 0.50 (95% CI 0.26-0.94: I 2 12%, p = 0.03). Conclusion: In women with endometrial polyp, menopausal age and thickened endometrium might increase the probability while tamoxifen or HRT use might lower the likelihood of endometrial pre-malignancy/malignancy; and the presence of AUB might signal endometrial pre-malignancy/malignancy.