(007) The Safety of Vaginal Estrogen Therapy for Genitourinary Syndrome of Menopause in Women with a History of Breast Cancer – A Claims Database Analysis

Abstract Introduction Systemic treatment for breast cancer (BC) may result in genitourinary syndrome of menopause (GSM) up to 70% postmenopausal BC survivors. Though systemic estrogen therapy is usually avoided these patients, vaginal be prescribed treat GSM symptoms. However, few eligible patients with and history are due concern recurrence. Objective Our objective was assess the recurrence rates by status women diagnosed a using large US claims database. Methods A health research network (the TriNetX Diamond Network) over 200 million queried from 2009 2022. Females diagnosis (C50, Z86.000) within five years before an initial (ICD-10 N90.5, N95.2) were included. Patients who underwent mastectomy (1015054), radiation oncology (1010843), and/or chemotherapy (1002) three months prior excluded as they considered have active disease. Recurrence defined need mastectomy, radiation, or after initiating GSM. We cancers other than 5 their diagnosis. The study cohort included those ≥3 (GU500) prescriptions, while control only without prescriptions. Propensity-matching between cohorts age, ethnicity, race, family neoplasm (Z80.3), overweight obesity (E66), hormone replacement (Z79.890), tobacco usage (Z72.0) conducted. sub-analysis positive receptor (+ER) (Z17.0), when available, performed. Results Amongst females following BC, 2,113 (5%) received 40,019 (95%) didn’t receive any +ER status, 410 (3.9%) 10,182 (96.1%) Compared matched controls, prescriptions (n=2,111) had similar risks procedures (relative risk (RR) 1.06 [95% CI 0.54, 2.06]), (RR 1.16 [0.98, 1.37]), [0.54, 2.11]) first prescription (Table 1). Individuals (n=409) procedures, chemotherapy, 1.07 [0.86, 1.33]) compared controls Conclusions In this claims-based analysis, we found treatment, which serve proxies recurrence, use personal These results suggest that not associated increased hence safe. Disclosure No