Abstract 275: The prevalence of endometrial cancer in women with postmenopausal bleeding: a systematic review and meta-analysis
Authors: Clarke Megan A. , Long Beverly J. , Morillo Arena Del Mar , Bakkum-Gamez Jamie N. , Wentzensen Nicolas 
Published: July 2017

Abstract
Background: Endometrial cancer is highly curable when detected early, but clinical symptoms are often missed. Most cancers arise in women with abnormal postmenopausal bleeding (PMB). However, PMB is not specific for endometrial cancers. In previous reports, the prevalence of endometrial cancer in women with PMB was reported to range from 3-25%. Because of the importance for guiding clinical management and endometrial cancer risk prediction, we conducted a systematic review and meta-analysis to obtain precise prevalence estimates of endometrial cancer in women with PMB.
Methods: A systematic review and meta-analysis summarized all peer-reviewed studies reporting endometrial cancer prevalence in women with PMB, published before Sept. 1, 2016. We calculated a pooled prevalence estimate and 95% confidence interval (CI) using a random-effects model, and quantified heterogeneity across studies using the I2 statistic. Subgroup meta-analyses were performed to investigate sources of variability according to selection criteria for endometrial thickness (ET) and hormone replacement therapy (HRT). We also stratified by study location to determine whether prevalence estimates varied by country or region if ≤5 studies included per country.
Results: 105 studies were included, contributing data for 37,000 women with PMB and 3,028 with cancer from 34 countries. Overall, the pooled prevalence of endometrial cancer in women with PMB was 11% (95% CI 10-12%), with I2 =94.3%. Among studies that selected women with a minimum ET (≥ 4mm; n=14), the pooled prevalence of endometrial cancer was 17% (95% CI 14-20%) compared with studies that did not select for ET (10%, 95% CI 9-11%). In studies that excluded women using HRT (n=34), the pooled prevalence of endometrial cancer was 15% (95% CI 12-17%) compared with studies that did not exclude women using HRT (9%, 95% CI 8-10%). Stratification by study location revealed variation in prevalence estimates. For example, in the United States (n=9) and the United Kingdom (n=16), prevalence of endometrial cancer was 4% (95% CI 2-7%) and 5% (95% CI 4-6%), respectively, whereas in Italy (n=14), the prevalence was 11% (95% 8-14%). Regional differences were also observed, ranging from 8% (95% CI 3-14%) in South Central Asia (n=5) to 18% (95% CI 12-23%) in Southern Europe (n=11).
Conclusions: The overall prevalence of endometrial cancer among unselected women with PMB is approximately 10% with substantial heterogeneity across studies. Marked geographic differences in the prevalence endometrial cancer were observed. Factors related to selection for ET and/or HRT use may partially contribute to this variability. Risk prediction models depend on precise prevalence estimates for accurate prediction and utility in clinical management. More research is needed to test the applicability of endometrial cancer risk prediction models in high-risk subgroups and in study populations from diverse geographic regions.
Citation Format: Megan A. Clarke, Beverly J. Long, Arena Del Mar Morillo, Jamie N. Bakkum-Gamez, Nicolas Wentzensen. The prevalence of endometrial cancer in women with postmenopausal bleeding: a systematic review and meta-analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 275. doi:10.1158/1538-7445.AM2017-275