Analysis of adjuvant chemotherapy and radiotherapy for stage II endometroid type endometrial cancer.

Abstract

e17118 Background: Endometrial cancer (EC) is the most common gynecologic malignancy. Stage II EC - involving the cervix - is ideally treated with primary surgical staging; however, adjuvant treatment is not well defined. Methods: The population included 8,506 patients with 2009 FIGO Stage II endometrioid-type EC treated surgically within the National Cancer Database. Patients were categorized into six treatment groups: 1. hysterectomy (HYS) alone; 2. HYS with external beam radiation therapy (EBRT); 3. HYS with chemotherapy (CT); 4. HYS with CT and EBRT; 5. HYS with vaginal brachytherapy (VBT); and 6. HYS with CT and VBT. Univariable frailty survival analysis (UVA) that allowed for clustering of patients was used to determine the effect of sociodemographic factors and comorbidities on time to death; a generalized linear mixed effects allowing random intercepts for each treatment facility type was also used to estimate the odds of receiving any treatment beyond HYS. Results: 3,571 (42%) underwent HYS alone, while 4,312 (51%) received HYS with adjuvant radiation therapy (ART), 251 (3%) received HYS with CT, and 372 (4%) received all three modalities. Of those that received ART, 2,951 (68%) had EBRT while 1,361 (32%) had VBT. On UVA, black race, years of education, government insurance or uninsured status, higher tumor grade, greater Charlson-Deyo comorbidity count (CDCC), increased age, tumor grade, and tumor size all predicted poor survival. On MVA, patients receiving ART were only 0.747 (95% CI: 0.641 – 0.871) times as likely to die at any given time when compared with HYS alone ( p = .0002). There was no difference in survival between radiation modalities. Further, compared to patients who only received HYS, those who received HYS+CT had comparable survival estimates ( p = .20) as did patients who received HYS+ART+CT ( p = .24). When controlling for all other factors, higher tumor grade, increased CDCC, age, or tumor size, and Medicaid insurance were hazardous predictors of time to death ( p< .05). Conclusions: In stage II EC patients, adjuvant EBRT and VBT improved survival. Adjuvant CT did not improve survival though this should be further studied given the infrequency it was delivered in this population.