Risk of occult atypical hyperplasia or cancer in women with nonatypical endometrial hyperplasia

Aim: The aim of this study was to identify subsets of patients diagnosed with nonatypical endometrial hyperplasia (NAEH) by endometrial biopsy who had high risk for occult atypical endometrial hyperplasia (AEH) or endometrial cancer (EC). Methods: We retrospectively reviewed the medical records of 281 patients who underwent hysterectomy within 6 months after a diagnosis of NAEH. We collected data on age, body mass index, menopausal status, tamoxifen use, previous history of NAEH, details of endometrial biopsy (location, curettage vs. pipelle sampling), NAEH subtype (simple vs. complex), interval between endometrial biopsy and hysterectomy, indication of hysterectomy and the presence of occult AEH or EC in hysterectomy specimen. Associations between variables and occult AEH or EC were analyzed. Risk of occult AEH or EC in subsets were calculated and visualized using a heatmap. Results: Among 281 patients, 34 (12.1%) and 9 (3.2%) had occult AEH and EC in hysterectomy specimens, respectively. Using univariate analysis, we found age, menopausal status and subtype were associated with occult AEH or EC. Using multivariate analysis, older age (odds ratio = 1.09, P < 0.01) and complex subtype (odds ratio = 3.34, P < 0.01) were independent risk factors. Patients at an age ≥ 51 years with complex NAEH had about 50% risk of occult AEH or EC. Conclusion: Women at an age ≥ 51 years with complex NAEH had high risk for occult AEH or EC and surgical treatment can be considered for these patients.