Patients with FIGO stage III endometrial cancer routinely receive adjuvant therapy. The purpose of this study was to evaluate overall survival (OS) and disease-free survival (DFS) in patients with stage IIIA to IIIC2 patients by treatment modality received and risk factors.
Patients with stage III endometrial cancer treated from 2000-2010 were identified in the provincial cancer registry. Clinicopathologic characteristics, adjuvant treatments and outcomes were compared using descriptive and multivariable analyses.
261 patients had stage 3 endometrial cancer, 132 with stage IIIA, 9 with IIIB, 85 with IIIC1 and 35 with IIIC2. 39 had FIGO grade 1 disease; 73, grade 2; 147, grade 3. 160 had endometrioid and 35 had serous carcinoma. 161 patients received sequential adjuvant chemotherapy (CT) and radiotherapy (RT); 33 received RT only; 32 received CT only; 35 received neither. 5-year (5Y) DFS and OS were similar among stage IIIA (DFS 46.7%, OS 58.5%), IIIB (DFS 50.8%, OS 58.5%), IIIC1 (DFS 44%, OS 49.9%) and IIIC2 (DFS 42%, OS 41.6%). Use of adjuvant RT was associated with improved median DFS (53.7 vs 14.7m, p<0.00001) and OS (61.9 vs 25.7m, p<0.00001) compared to no RT. Likewise, use of adjuvant CT was also associated with improved DFS (54.8 vs 16.5m, p<0.00001) and OS (62.9 vs 26.5m, p<0.00001) compared to no CT. Those who received both chemotherapy and radiotherapy had better outcomes with 5-year DFS (58.3%) and OS (65.2%), compared with those who received monotherapy. On multivariate analysis, grade 3 disease, deep myometrial invasion >50%, and no adjuvant RT or CT were identified as adversely impacting DFS and OS.
In stage III endometrial cancer patients, use of both chemotherapy and radiation therapy was associated with improved DFS and OS and therefore should be recommended in all eligible patients after resection.