Validation Of The Esmo-Esgo-Estro Consensus Conference Risk Grouping In Turkish Endometrial Cancer Patients Treated With Comprehensive Surgical Staging

To validate the ESMO-ESGO-ESTRO consensus risk grouping in endometrial cancer (EC) patients treated with external beam radiotherapy (EBRT) and/or vaginal brachytherapy (VBT) ± chemotherapy (CT) after comprehensive surgical staging. 683 patients treated in four institutions were retrospectively evaluated. Patients were classified into 4 groups: low-risk (LR), intermediate risk (IR), high-intermediate risk (HIR), and high-risk (HR). VBT was performed in patients with deep myometrial invasion (MI) or grade 3 histology. EBRT±VBT was performed when cervical stromal invasion, positive/close surgical margin, or extra-uterine extension was found. Adjuvant CT was applied in patients with stage III disease and non-endometrioid histology (NEH). Median follow-up was 56 months. 5-year overall survival (OS) and relapse-free survival (RFS) rate was 86% and 83%, respectively. A significant difference in OS was found between LR and HR groups (p=0.03) and a trend between LR and HIR groups (p=0.054). RFS rates were significantly different between LR and HIR (p=0.04), LR and HR (p=0.007), and IR and HR groups (p=0.01). No statistically significant difference was found in OS and RFS between HIR and HR groups. Median time to recurrence was 53 months. Loco-regional recurrence (LRR) and distant metastasis (DM) developed in 41 (6%) and 68 (10%) patients, respectively. Twenty (3%) patients had both LRR and DM. LRR and DM were significantly higher in the HIR and HR groups compared to other groups (p=0.009 and p=0.003, respectively). Two- and 5-year OS and RFS rate in the HR subgroups is listed in Table 1. OS rate was significantly higher in stage IB-grade 3 and stage II compared to stage III and NEH. There was no statistically significant difference between stage IB-grade 3 and stage II (p=0.9), and between stage III and NEH (p=0.4). RFS rate was significantly higher in stage IB-grade 3 and stage II compared to stage III and NEH. There was no significant difference between stage IB-grade 3 and stage II (p=0.5), and stage III and NEH (p=0.8). The current risk grouping does not clearly discriminate the HIR and IR groups. Putting the stage IB-grade 3 and stage II with stage III and NEH in the same prognostic group may be misleading. In patients with comprehensive surgical staging, a further risk grouping is needed to distinguish the real HR group.Abstract 2805; Table 1Characteristic2y OS (%)5y OS (%)2y RFS (%)5y RFS (%)IB-G398919788II96898983III93758970NEH86768272 Open table in a new tab