Identifying women 45 years and younger at elevated risk for endometrial hyperplasia or cancer

To estimate the prevalence of, and identify risk factors associated with, endometrial hyperplasia and/or cancer (EH/EC) in patients ≤45 years old undergoing endometrial sampling for abnormal uterine bleeding (AUB).

We performed a retrospective cohort study of patients 18-45 years old with AUB who underwent endometrial sampling between 2016 and 2019 within a US-based multi-hospital system using billing code queries. We used multivariable Poisson regression to identify factors associated with EH/EC and calculated prevalence stratified by these factors. We estimated predicted probabilities within combinations of characteristics in order to examine the range of risk in this population.

Among 3175 patients, median age was 39 years (interquartile range [IQR]:35-43) and BMI was 29.7 kg/m² (IQR: 24.2-36.9). Thirty-nine percent were non-Hispanic White, 41% non-Hispanic Black, 9% Hispanic, and 11% Asian/Other/Unknown. BMI and polycystic ovarian syndrome (PCOS) were associated with higher EH/EC risk; non-Hispanic Black race was associated with lower risk. EH/EC prevalence ranged from 2% in BMI <25 to 16% in BMI ≥50 kg/m² (p-trend <0.001). These prevalence estimates differed by race/ethnicity with the lowest estimates in non-Hispanic Black patients (0.5% BMI <25 vs. 9% BMI ≥50) and highest in Hispanic patients (1.5% BMI <25 vs. 33% BMI ≥50). Accounting for combinations of risk factors, predicted probabilities were highest - 34-36% - among patients with PCOS, diabetes, BMI ≥50, and Hispanic or Asian/Other/Unknown race/ethnicity.

When accounting for combinations of key risk factors, risk of EH/EC in patients ≤45 years old with AUB ranges widely; the more nuanced estimates of risk presented here could help inform clinical decision-making about endometrial sampling in this population.