Long-Term Outcome of Postmenopausal Women With Proliferative Endometrium on Endometrial Sampling

Background Proliferative endometrium has been reported in 15% of endometrial biopsies of women aged 50 years and older. Contrary to endometrial hyperplasia, proliferative endometrium has not been associated with the risk of endometrial cancer. Objective This study aimed to report on the long-term outcome of postmenopausal women who received a diagnosis of proliferative endometrium. Study Design This is a retrospective cohort study of 1808 women aged 55 years and older who underwent endometrial sampling between January 1997 and December 2008. Outcome data were available through February 2018. Women with a proliferative endometrium were compared with those with an atrophic endometrium for future development of endometrial hyperplasia or cancer. A subanalysis was performed for those who presented with postmenopausal bleeding. Uni- and multivariable logistic regression analyses were used to assess for confounders. Results In this study, 297 women (16.4%) received a diagnosis of proliferative endometrium. Furthermore, 962 women met the inclusion criteria. Among those women, 278 had a proliferative endometrium, and 684 had an atrophic endometrium. Women with a proliferative endometrium were younger (61.2 vs 64.5 years; P 60 years (odds ratio, 1.98; 95% confidence interval, 1.03–3.82; P=.04), and body mass index >35 kg/m2 (odds ratio, 2.3; 95% confidence interval, 1.09–4.83; P Conclusion One of the 6 postmenopausal women who underwent endometrial sampling had a proliferative endometrium. Furthermore, 11.9% of women developed endometrial hyperplasia or cancer, a 4-fold greater incidence than women with an atrophic endometrium. The findings of this study suggest that long-term monitoring is warranted for women with postmenopausal bleeding and a proliferative endometrium histology. Further studies are needed to examine if a treatment is required to negate the risk of unopposed estrogen.