Radiation and hormonal therapy for primary treatment of stage I endometrial cancer and long-term survival

Objectives: Estimate the association between non-surgical management (NSM) (e.g. hormonal or radiation therapy) and overall survival among women with stage I endometrioid endometrial cancer (EEC) and identify patient and facility characteristics associated with receipt of NSM. Methods: Women >45 years of age with clinical stage I EEC were identified in the National Cancer Database from 2004 to 2016. Women treated with NSM were compared with women treated initially with hysterectomy. Patient and facility characteristics associated with NSM were evaluated using logistic regression models. Association with overall survival was examined using log-rank tests, Kaplan-Meier curves, and Cox proportional hazards regression models with and without propensity score matching (PSM). Results: A total of 112,469 women underwent treatment for stage I EEC between 2004 and 2016. 2776 (3%) received NSM, of whom 1987 (71%) received radiation therapy, 688 (25%) received hormonal therapy, and 101 (4%) received both. Older age, black race, higher Charlson-Deyo scores, Medicaid insurance, and low annual facility hysterectomy volume were associated with receiving NSM. The 5-year survival rate was 40% (95%CI: 37%–42%) for women with NSM compared to 89% (95%CI: 88%–89%) for hysterectomy. Women treated with NSM died at a faster rate than those who underwent primary hysterectomy (HR 7.6, 95%CI: 7.2–8.0; p < 0.001). This statistically significant difference in survival persisted in adjusted Cox proportional hazards models and after PSM. Conclusions: Women treated with NSM had a significantly higher risk of death compared to those undergoing hysterectomy for stage I EEC. Caution should be used when selecting patients for NSM given its worse outcomes.