What Ultrasound Endometrial Thickness Threshold Better Detects Cancer and Atypical Hyperplasia in Asymptomatic Postmenopausal Women

Study Objective Postmenopausal women with incidental thickened endometrium (≥4mm) on transvaginal ultrasound (TVUS) will usually undergo hysteroscopy and curettage despite having a low absolute risk of endometrial cancer (EC) or atypical hyperplasia (AH). This review examines whether an increased TVUS endometrial thickness (ET) threshold has superior diagnostic accuracy for endometrial malignancies and premalignancies in asymptomatic postmenopausal women. Design Systematic literature review. Setting N/A. Patients or Participants N/A. Interventions Pubmed, EMBASE and Cochrane Database of Systematic Reviews were electronically searched to identify articles published between 2011 and 2021 investigating ET and endometrial pathology in asymptomatic postmenopausal women. The quality of evidence of included articles was evaluated. Measurements and Main Results Seven studies reported the diagnostic accuracy of alternative ET thresholds for EC in asymptomatic postmenopausal women. Better evidence identified 12mm as the optimal threshold (AUC ROC 0.716, 95% CI 0.534-0.897, P=0.019). Remaining studies identified 7.2mm to 15mm as optimal cut-off points. Seven studies investigated a threshold for both EC and AH. A higher quality study identified a threshold of 11mm as optimal (AUC ROC 0.587, 95% CI 0.465-0.708) but this finding was not significant (P=0.144). Remaining studies identified optimal thresholds of 10mm to 13.5mm. A new diagnostic strategy is only useful if it improves patient outcomes. Only one study reported adverse events. Four studies had nil insufficient endometrial sample rates at hysteroscopy while insufficient sampling occurred in 57/900 (6.3%) and 52/276 (18.8%) in two studies, reflecting a significant risk of patients undergoing a procedure without benefit. Conclusion Evidence for alternative ET thresholds for improved detection of EC and AH is not rigorous, and confidence intervals were often wide reflecting uncertainty. It is important for research in this area to consider patient outcomes. Long-term follow up in asymptomatic postmenopausal women with increased ET is appropriate and further evaluation may be prompted by ET of 10mm or more, increasing ET over time and existing risk factors.