Vaginal estrogen therapy utilization and associated outcomes in younger survivors of endometrial cancer

Objectives: – To evaluate the utilization of vaginal estrogen therapy (ET) and outcomes associated with its use among younger endometrial cancer survivors, using a propensity score-matched cohort. Methods: – We conducted a cohort study using data from the TriNetX database’s US Collaborative Network, which includes electronic health records and insurance claims data from 68 health care organizations. Women 18-51 years old diagnosed with endometrial cancer between November 1, 2005, and December 31, 2023, were included. We used 1:1 propensity score matching to create cohorts with and without vaginal ET in the year after their endometrial cancer diagnosis. We estimated hazard ratios (HRs) with 95% CIs for the primary outcome of endometrial cancer recurrence and assessed the risks of negative control outcomes. Results: – We identified 1, 412 endometrial cancer survivors with vaginal ET and 23, 859 without vaginal ET. After propensity score matching, the vaginal ET and non-ET groups included 1, 412 individuals each. The mean ET treatment duration was 1.88 years (SD, 0.36 y). Endometrial cancer recurrence risk was not increased among those with vaginal ET use (HR, 0.87; 95% CI, 0.60-1.27). Conclusions: – Endometrial cancer survivors with short-term exposure to vaginal ET did not have an elevated risk of endometrial cancer recurrence compared with those without vaginal ET.