Long-term risk of endometrial cancer following postmenopausal bleeding and reassuring endometrial biopsy.

INTRODUCTION: Women with postmenopausal bleeding and endometrial thickness >4 mm undergo endometrial sampling to exclude endometrial cancer. The aim of this study is to investigate the relative risk of developing endometrial cancer in a prospective cohort after initial work-up for postmenopausal bleeding showing reassuring histology or insufficient sampling.

MATERIAL AND METHODS: All women presenting with postmenopausal bleeding were prospectively included from January 2009 to April 2011. Follow-up data were collected from patient charts and PALGA (Dutch Pathology Registry). Hazard ratios for endometrial cancer were determined by calculating standardized incidence ratios.

RESULTS: A total of 668 women were included and 568 women were available for follow-up [median follow-up time 47 (range 7-63) months]. Women who presented with postmenopausal bleeding, endometrial thickness >4 mm and hyperplasia without atypia on biopsy at the first presentation showed a significantly increased risk (standardized incidence ratio 17.15, 95% confidence interval 1.96-61.93) of being diagnosed with endometrial cancer during the first four years of follow up compared with the age-specific population. All women that developed endometrial cancer after initial reassuring histology presented with recurrent postmenopausal bleeding. None of the women with endometrial thickness >4 mm and no or insufficient sample for histology at the first presentation developed endometrial cancer during the follow up.

CONCLUSIONS: Although in general, women with endometrial hyperplasia without atypia are considered to have a low risk for cancer, we observed a significant long-term risk of endometrial cancer after postmenopausal bleeding. Whether additional diagnostics or a more stringent follow-up regimen would be cost-effective, needs to be studied.