Heterogeneity of outcomes of endometrial cancer patients included in prospective clinical trials

To assess heterogeneity in five-year overall survival of patients with endometrial cancer using a large retrospective database with cohorts defined by recent prospective clinical trials. The National Cancer Database was used to identify patients with endometrial cancer who underwent hysterectomy from 2004 to 2016. The reported inclusion criteria for GOG-249, PORTEC-3, and GOG-258 were used to define the respective cohorts. Five-year overall survival for each cohort was stratified by tumor characteristics and adjuvant therapy regimens. A total of 89,133 patients were identified who would have fulfilled the entry criteria to GOG-249, PORTEC-3, or GOG-258. When stratified by tumor characteristics, irrespective of adjuvant therapy, five-year overall survival ranged from 59.9%–81.7% for patients meeting GOG-249 inclusion criteria, 40.2%–81.8% for patients meeting PORTEC-3 inclusion criteria, and 17.5%–75.0% for those meeting GOG-258 inclusion criteria. Analysis of subgroups by adjuvant therapy regimen revealed significant improvement in five-year overall survival for chemoradiotherapy compared to chemotherapy or radiotherapy alone for endometroid stage III and stage IVA disease and for some stages of serous and clear cell histology. Recent prospective trials of adjuvant therapy for endometrial cancer have included heterogeneous cohorts of patients based on five-year overall survival rates when the populations are stratified by tumor characteristics. The variation in expected five-year overall survival for subsets of patients may result in underpowered studies or misleading results. •Recent prospective trials of adjuvant therapy for endometrial cancer have included heterogenous cohorts of patients.•5-year survival was 60–82% for patients meeting GOG-249 criteria, 40–82% for PORTEC-3, and 18–75% for GOG-258 criteria.•The variation in expected survival for subsets of patients may result in underpowered studies or misleading results.