Risk assessment of endometrial cancer and endometrial intraepithelial neoplasia in women with abnormal bleeding and implications for clinical management algorithms

© 2020 Background: Most endometrial cancer cases are preceded by abnormal uterine bleeding, offering a potential opportunity for early detection and cure of endometrial cancer. Although clinical guidelines exist for diagnostic workup of abnormal uterine bleeding, consensus is lacking regarding optimal management for women with abnormal bleeding to diagnose endometrial cancer. Objective: We report the baseline data from a prospective clinical cohort study of women referred for endometrial evaluation at the Mayo Clinic, designed to evaluate risk stratification in women at increased risk for endometrial cancer. Here, we introduce a risk-based approach to evaluate diagnostic tests and clinical management algorithms in a population of women with abnormal bleeding undergoing endometrial evaluation at the Mayo Clinic. Study Design: A total of 1163 women aged ≥45 years were enrolled from February 2013 to May 2019. We evaluated baseline absolute risks and 95% confidence intervals of endometrial cancer and endometrial intraepithelial neoplasia according to clinical algorithms for diagnostic workup of women with postmenopausal bleeding (assessment of initial vs recurrent bleeding episode and endometrial thickness measured through transvaginal ultrasound). We also evaluated risks among women with postmenopausal bleeding according to baseline age (\u3c60 vs 60+ years) as an alternative example. For this approach, biopsy would be conducted for all women aged 60+ years and those aged \u3c60 years with an endometrial thickness of \u3e4 mm. We assessed the clinical efficiency of each strategy by estimating the percentage of women who would be referred for endometrial biopsy, the percentage of cases detected and missed, and the ratio of biopsies per case detected. Results: Among the 593 women with postmenopausal bleeding, 18 (3.0%) had endometrial intraepithelial neoplasia, and 47 (7.9%) had endometrial cancer, and among the 570 premenopausal women with abnormal bleeding, 8 (1.4%) had endometrial intraepithelial neoplasia, and 7 (1.2%) had endometrial cancer. Maximum risk was noted in women aged 60+ years (17.7%; 13.0%–22.3%), followed by those with recurrent bleeding (14.7%; 11.0%–18.3%). Among women with an initial bleeding episode for whom transvaginal ultrasound was recommended, endometrial thickness did not provide meaningful risk stratification: risks of endometrial cancer and endometrial intraepithelial neoplasia were nearly identical in women with an endometrial thickness of \u3e4 mm (5.8%; 1.3%–10.3%) and ≤4 mm (3.6%; 0.9%–8.6%). In contrast, among those aged \u3c60 years with an endometrial thickness of \u3e4 mm, the risk of endometrial cancer and endometrial intraepithelial neoplasia was 8.4% (4.3%–12.5%), and in those with an endometrial thickness of ≤4 mm, the risk was 0% (0.0%–3.0%; P=.01). The most efficient strategy was to perform biopsy in all women aged 60+ years and among those aged \u3c60 years with an endometrial thickness of \u3e4 mm, with the lowest percentage referred to biopsy while still detecting all cases. Conclusion: Existing clinical recommendations for endometrial cancer detection in women with abnormal bleeding are not consistent with the underlying risk. Endometrial cancer risk factors such as age can provide important risk stratification compared with the assessment of recurrent bleeding. Future research will include a formal assessment of clinical and epidemiologic risk prediction models in our study population as well as validation of our findings in other populations

A prospective clinical cohort study of women at increased risk for endometrial cancer.

OBJECTIVE: To evaluate endometrial cancer (EC) risk assessment and early detection strategies in high-risk populations, we designed a large, prospective cohort study of women undergoing endometrial biopsy to assess risk factors and collect novel biospecimens for future testing of emerging EC biomarkers. Here we report on the baseline findings of this study. METHODS: Women aged ≥45 years were enrolled at the Mayo Clinic from February 2013 – June 2018. Risk factors included age, body mass index (BMI), smoking, oral contraceptive and hormone therapy use, and parity. We collected vaginal tampons, endometrial biopsies, and Tao brush samples. We estimated mutually-adjusted odds ratios (OR) and 95% confidence intervals (CI) using multinomial logistic regression; outcomes included EC, atypical hyperplasia, hyperplasia without atypia, disordered proliferative endometrium, and polyps, versus normal endometrium. RESULTS: Subjects included 1,205 women with a mean age of 55 years; 55% were postmenopausal, and 90% had abnormal uterine bleeding. The prevalence of EC was 4.1% (n=49), predominantly diagnosed in postmenopausal women (85.7%). Tampons and Tao brushings were obtained from 99% and 68% of women, respectively. Age (OR 1.14, 95% CI 1.1– 1.2) and BMI (OR 1.39, 95% CI 1.1–1.7) were positively associated with EC; atypical hyperplasia (OR 1.07, 95% CI 1.0–1.1; OR 2.00, 95% CI 1.5–2.6, respectively), and polyps (OR 1.06, 95% CI 1.0–1.1; OR 1.17, 95% CI 1.0–1.3, respectively); hormone therapy use and smoking were inversely associated with EC (OR 0.42, 95%, 0.2–0.9; OR 0.43, 95% CI, 0.2–0.9, respectively). Parity and past oral contraception use were not associated with EC. CONCLUSIONS: Well-established EC risk factors may have less discriminatory accuracy in high-risk populations. Future analyses will integrate risk factor assessment with biomarker testing for EC detection