Adjuvant hormone therapy and overall survival among low-grade and apparent early-stage endometrial stromal sarcoma patients

Objective: Surgery is the mainstay of treatment for low-grade endometrial stromal sarcoma (LG-ESS). While adjuvant hormone therapy is recommended for patients with advanced/recurrent disease, no consensus regarding its use among early-stage patients exists. We aimed to identify correlates of adjuvant hormone therapy use and associations of adjuvant hormone therapy and overall survival (OS) in stage I LG-ESS patients.

Methods: Retrospective cohort study of patients with stage I LG-ESS who underwent hysterectomy from 2004-2019 using data from the National Cancer Database. Categorical data were compared using χ² tests. Kaplan-Meier estimates and log-rank tests were used to compare OS according to adjuvant hormone use. Hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between adjuvant hormone use and OS were estimated using Cox proportional hazards regression.

Results: Of 2,386 patients included, 20.2% were treated with adjuvant hormonal therapy. Use of hormone therapy increased over time, with rates approximately doubling from 2004 to 2019 (12.6% to 24.6%). Age, tumor size, lymphovascular space invasion and adjuvant radiation were associated with adjuvant hormone therapy use. There was no association between adjuvant hormone therapy and OS (log-rank p=0.73; HR=1.05; 95% CI 0.76-1.46) for patients with LG-ESS.

Conclusion: Use of adjuvant hormone therapy for stage I LG-ESS has increased over time though is not associated with OS in this cohort of patients. Additional evaluation is needed to understand the impact of adjuvant hormone therapy on recurrence rates, progression rates, and quality of life to fully understand its value.