ObjectivesThe primary objective was to determine the prevalence of endometrial cancer in asymptomatic and symptomatic postmenopausal women referred to the hysteroscopy service for incidental finding of thickened endometrium. The secondary objectives were to identify, for the asymptomatic cohort, an acceptable threshold of endometrial thickness (ET) which should trigger endometrial sampling and its related sensitivity and specificity.MethodsThis was a retrospective cohort study of 136 asymptomatic and 602 symptomatic postmenopausal women with an ET of >4 mm referred to the endometrial cancer diagnostic service in a gynecology oncology center over a period of one year. Clincal and demographic data were analyzed. Histopathological diagnosis was completed and receiver operating characteristic (ROC) curves for acceptable ET cutoff in asymptomatic women were evaluated.ResultsThe prevalence of malignancy and atypical hyperplasia in asymptomatic women was 3.7% and 4.4%, respectively. Within the asymptomatic subgroup with ET <11 mm, the yield rate for atypical hyperplasia (AH)+cancer was 2.2%. An ET <10 mm gave a similar yield; however, specificity decreased. ET (t-test p-value=0.037) correlates with endometrial pathology. Receiver operating characteristic (ROC) curves identified a cutoff of 11 mm as an acceptable threshold for triggering further investigations.ConclusionBased on our findings, 11 mm may represent an acceptable threshold for further investigation in asymptomatic postmenopausal women. We strongly advocate qualitative assessment of the endometrium and evaluation of individual risk factors in women with ET between 4 mm and 11 mm. This study will contribute to the existing body of evidence for the management of asymptomatic postmenopausal women with incidental increased ET. Further studies are required.