Adjuvant treatment and outcomes for patients with stage IIIA grade 1 endometrioid endometrial cancer

Abstract

ObjectiveThe role and type of adjuvant therapy for patients with International Federation of Gynecology and Obstetrics (FIGO) stage IIIA grade 1 endometrioid endometrial adenocarcinoma are controversial. This retrospective cohort study aimed to determine associations between adjuvant therapy use and survival among patients with stage IIIA grade 1 endometrial cancer.MethodsPatients who underwent primary surgery for stage IIIA (FIGO 2009 staging) grade 1 endometrial cancer between January 2004 and December 2016 were identified in the National Cancer Database. Demographics and receipt of adjuvant therapy were compared. Overall survival was analyzed using Kaplan–Meier curves, log-rank test, and multivariable Cox proportional hazard models.ResultsOf 1120 patients, 248 (22.1%) received no adjuvant treatment, 286 (25.5%) received chemotherapy alone, 201 (18.0%) radiation alone, and 385 (34.4%) chemotherapy and radiation. Five-year overall survival rate was 83.0% (95% CI 80.1% to 85.6%). Older age, increasing comorbidity count, and lymphovascular space invasion status were significant negative predictors of survival. Over time, there was an increasing rate of chemotherapy (45.4% in 2004–2009 vs 69.2% in 2010–2016; p<0.001). In the multivariable analysis, chemotherapy was associated with significantly improved overall survival compared with no adjuvant therapy (HR 0.49 (95% CI 0.31 to 0.79); p=0.003). There was no survival association when comparing radiation alone with no treatment, and none when adding radiation to chemotherapy compared with chemotherapy alone. Those with lymphovascular space invasion (n=124/507) had improved overall survival with chemotherapy and radiation (5-year overall survival 91.2% vs 76.7% for chemotherapy alone and 27.3% for radiation alone, log-rank p<0.001), but there was no survival difference after adjusting for age and comorbidity (HR 0.25 (95% CI 0.05 to 1.41); p=0.12).ConclusionsThe use of adjuvant chemotherapy for the treatment of stage IIIA grade 1 endometrial cancer increased over time and was associated with improved overall survival compared with radiation alone or chemoradiation. Patients with lymphovascular space invasion may benefit from combination therapy.