Factors Associated with Malignancy in Hysteroscopically Resected Endometrial Polyps: A Systematic Review and Meta-Analysis

In this study, we aimed to estimate the frequency of premalignant and malignant lesions in endometrial polyps, and to evaluate associated clinical and demographic factors. A literature search was performed in major databases and the gray literature using the terms polyps OR endometrial polyp AND endometrial neoplasms OR endometrial cancer OR endometrial hyperplasia OR malignan*. Studies describing the frequency of premalignant and malignant lesions in endometrial polyps and any clinical or demographic factors associated with malignant lesions extracted using hysteroscopy were considered eligible. Independent investigators selected the studies and extracted the data. A meta-analysis was performed using a random-effects model and meta-regression. We identified 37 studies (comprising 21,057 patients) of endometrial polyps. The prevalence of premalignant and malignant lesions was 3.4% (95% confidence interval [CI], 2.8-4.1; I2, 80.5%). Abnormal uterine bleeding (prevalence ratio [PR], 1.47; 95% CI, 1.27-1.69; I2, 82.4%), menopausal status (PR, 1.67; 95% CI, 1.48-1.89; I2, 78.4%), age >60 years (PR, 2.41; 95% CI, 1.84-3.16; I2, 81.5%), diabetes mellitus (PR, 1.76; 95% CI, 1.43-2.16; I2, 0.0%), systemic arterial hypertension (PR, 1.50; 95% CI, 1.20-1.88; I2, 75.9%), obesity (PR, 1.41; 95% CI:1.13-1.76; I2, 41.2%), and tamoxifen use (PR, 1.53; 95% CI, 1.06-2.21; I2, 0.0%) were associated with endometrial polyp malignancy. However, breast cancer (PR, 0.83; 95% CI, 0.44-1.57; I2, 0.0%), hormonal therapy (PR, 0.93; 95% CI, 0.67-1.30; I2, 31.7%), parity (PR, 0.87; 95% CI, 0.39-1.96; I2, 78.1%), and endometrial polyp size (PR, 1.05; 95% CI, 0.70-1.57; I2, 44.7%) were not associated with malignancy of endometrial polyps. Three of every 100 women with clinically recognized polyps, a condition associated with specific clinical and demographic factors, will harbor premalignant or malignant lesions.