SATEN III-Splitting Adjuvant Treatment of stage III ENdometrial cancers: an international, multicenter study

Abstract

Introduction The purposes of this study were to compare adjuvant treatment modalities and to determine prognostic factors in stage III endometrioid endometrial cancer (EC). Methods SATEN III was a retrospective study involving 13 centers from 10 countries. Patients who had been operated on between 1998 and 2018 and diagnosed with stage III endometrioid EC were analyzed. Results A total of 990 women were identified; 317 with stage IIIA, 18 with stage IIIB, and 655 with stage IIIC diseases. The median follow-up was 42 months. The 5-year disease-free survival (DFS) of patients with stage III EC by adjuvant treatment modality was 68.5% for radiotherapy (RT), 54.6% for chemotherapy (CT), and 69.4% for chemoradiation (CRT) (p=0.11). The 5-year overall survival (OS) for those patients was 75.6% for RT, 75% for CT, and 80.7% for CRT (p=0.48). For patients with stage IIIA disease treated by RT versus CT versus CRT, the 5-year OS rates were 75.6%, 75.0%, and 80.7%, respectively (p=0.48). Negative peritoneal cytology (HR: 0.45, 95% CI: 0.23 to 0.86; p=0.02) and performance of lymphadenectomy (HR: 0.33, 95% CI: 0.16 to 0.77, p=0.001) were independent predictors for improved OS for stage IIIA EC. For women with stage IIIC EC treated by RT, CT, and CRT, the 5-year OS rates were 78.9%, 67.0%, and 69.8%, respectively (p=0.08). Independent prognostic factors for better OS for stage IIIC disease were age <60 (HR: 0.50, 95%CI: 0.36 to 0.69, p<0.001), grade 1 or 2 disease (HR: 0.59, 95% CI: 0.37 to 0.94, p=0.014; and HR: 0.65, 95%CI: 0.46 to 0.91, p=0.014, respectively), absence of cervical stromal involvement (HR: 063, 95% CI: 0.46 to 0.86, p=0.004) and performance of para-aortic lymphadenectomy (HR: 0.52, 95% CI: 0.35 to 0.72, p<0.001). Discussion Although not statistically significant, CRT seemed to be a better adjuvant treatment option for stage IIIA endometrioid EC. Systematic lymphadenectomy seemed to improve survival outcomes in stage III endometrioid EC.