Clarke, Megan A.

Abstract Background: Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries and the incidence and mortality of EC continue to rise in the US. When detected early, EC is highly curable, suggesting that early detection strategies could reduce EC mortality. Women who develop EC often have a prolonged history of abnormal bleeding, offering a window for identifying many at-risk women prior to the development of advanced cancer. To evaluate risk prediction, novel sampling and early detection strategies in women at increased risk of EC, we established a prospective cohort of women with abnormal bleeding that is followed for endometrial hyperplasia and cancer endpoints. Methods: We consecutively enrolled women ≥45 years old presenting to the Mayo Clinic for evaluation of abnormal uterine bleeding (AUB), postmenopausal bleeding (PMB), thickened endometrial stripe (ES) on imaging, or Lynch Syndrome (LS). From all women, an intravaginal tampon and an endometrial brushing via Tao brush were collected before endometrial biopsy. Epidemiological EC risk factor data, clinical data, and endometrial biopsy histology results were abstracted from medical records. Absolute risk of endometrial hyperplasia and EC were calculated overall and in strata based on clinical symptoms and risk factors. Results: Among the first 1,000 women enrolled into the study, 712 (71%) were overweight or obese, 534 (53%) were postmenopausal, and 214 (22%) were current hormone replacement therapy (HRT) users. Endometrial biopsy and, if indicated, subsequent hysterectomy, detected 39 ECs, 16 atypical hyperplasias, and 28 hyperplasias without atypia at baseline evaluation. Among 534 postmenopausal women, 453 (85%) reported any type of bleeding, with spotting (39%) and light bleeding (27%) being more common than heavy bleeding (14%). Among perimenopausal women with AUB (n=452), the absolute risk of EC at baseline was 0.9% and among women with PMB, the absolute risk of EC at baseline was 7.5%. Among women with PMB, EC risk was modified by HRT use (risk of 2.6% in women on HRT and 8.2% in women not on HRT, respectively), obesity (risk of 5.3%, 8.1% and 9.5% for women with normal, overweight, and obese BMI, respectively), and type of bleeding (risk of 9.7%, 4.9%, and 8.2% in women with spotting, light or heavy bleeding, respectively). Discussion: While risk of endometrial cancer in perimenopausal women with AUB is low, approximately 8% of women presenting for clinical work up of PMB have underlying EC. Clinical presentation and risk factors modify the absolute risk of EC and may inform clinical management. Additional recruitment and prospective follow-up is underway to improve estimates of short- and long-term EC risk in women with PMB. With its collection of tampon and Tao brush samples, the study will provide a unique resource to evaluate molecular markers of EC and EC risk in elevated-risk women. Citation Format: Nicolas A. Wentzensen, Megan Clarke, Viji Shridhar, Maureen Lemens, Matthew Hopkins, Lisa Ahlberg, Shannon Laughlin-Tommaso, Karl Podratz, Mark Sherman, Jamie Bakkum-Gamez. A prospective study of endometrial cancer detection in women presenting for evaluation of abnormal peri- and postmenopausal bleeding [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2203.

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