ESTRO 2025 - Abstract Book

S810

Clinical - Gynaecology

ESTRO 2025

1426

Mini-Oral Patient characteristics and primary treatment approach ; A population based stage I-III endometrial cancer patients in the Netherlands over 1995-2022. Heidi Rütten 1 , Hans HB Wenzel 2 , Mieke ten Eikelder 3 , Michiel Simons 4 , Maaike A van der Aa 2 , Johan Bussink 1 , Johanna MA Pijnenborg 3 1 Radiation oncology, Radboud University Medical Centre, Nijmegen, Netherlands. 2 Research and Development, Netherlands Comprehensive Cancer Organisation, Utrecht, Netherlands. 3 Obstetrics & Gynaecology, Radboud University Medical Centre, Nijmegen, Netherlands. 4 Pathology, Radboud University Medical Centre, Nijmegen, Netherlands Purpose/Objective: Patients with endometrial cancer (EC) are often elderly with comorbidity and obesity. Treatment options might be limited in fragile patients. Aim of this study was to correlate patient factors with primary treatment and outcome in a population-based study in the Netherlands. Material/Methods: All patients with FIGO stage I-III EC diagnosed between 1995 and 2022 were included from the Netherlands Cancer Registry (NCR). Data on histology, stage, primary treatment, comorbidity (Charlson Comorbidity Index (CCI)), body mass index (BMI), age and survival were collected and analysed. Results: A total of 43.443 patients were included from the NCR. Most patients were diagnosed with endometroid endometrial cancer (89%) and FIGO stage I-II disease (87%). Over time the incidence of EC increased with a shift towards more non-endometroid cancers (NEEC). Survival increased from 72% in the earlier years (1995-1999) to 77% in later cohorts (2010-2019). The majority (95%) of patients underwent surgery as primary treatment. Patients who underwent a non-surgical approach were significantly older (82 versus 67 yr, p<0,001), with more comorbidity (CCI > 2 13% vs 3%) and a higher BMI (30 vs 29 kg/m 2 ) (table 1). Of the inoperable patients 45% (n=1053) did not receive any treatment. Whereas the 55% (n=1283) that were treated received either hormonal therapy (65%, n=840), (chemo)radiotherapy (external beam and brachytherapy) (7%, n=88)) or otherwise (radiotherapy external or internal or chemotherapy) (28%, n=355). Less than 1% of patients were treated with radiotherapy with curative intent defined as combined external beam radiotherapy and brachytherapy. The 5-year survival for patients treated with surgery was 79%, compared to 29% for patients with curative radiotherapy and only 13% for those treated with hormonal therapy.