Article Text
Abstract
Introduction Endometrial cancer incidence is increasing in the UK, but it is unclear whether this is due to an increase in endometrial hyperplasia (EH), the precursor lesion of many endometrioid carcinomas. We aimed to investigate, for the first time, trends in EH diagnosis rates over a 13-year period in a UK population.
Methods The Northern Ireland (NI) Endometrial Hyperplasia Register (NIEHR) contains all EH diagnoses in NI between 2008-2020. European age-standardised annual EH incidence rates were calculated per 100,000, and per 100 endometrial samples. Linkage to the NI Cancer Registry identified concurrent endometrial cancers (within three months before or after EH diagnosis).
Results A total of 2,808 women were diagnosed with EH: 1,857 (66%) with EH without atypia and 943 (34%) with atypical EH. Overall, EH incidence rates reduced by 28.5%, reducing from 37.5/100,000 during 2008–2011 to 26.8/100,000 during 2016–2019, which was similar by EH type (table 1, and figure 1). A further reduction in EH diagnoses was observed in 2020 (17.0/100,000), likely due to the COVID-19 pandemic. The reduction in incidence was more marked than corresponding reductions in endometrial sampling rates (18.8% reduction in EH incidence/100 samplings). The prevalence of concurrent endometrial cancer was 8.6%; and was much higher in atypical EH (21.7%) than EH without atypia (1.8%).
Conclusion/Implications We observed a reduction in the incidence of EH over time, which cannot be fully explained by reductions in endometrial sampling. However, this may also reflect evolving trends in EH diagnosis with the advent of greater pathological subspecialisation.