Trends in the incidence and survival outcomes of endometrial cancer in Korea: A nationwide population-based cohort study (355)

Abstract

<b>Objectives:</b> This nationwide cohort study aimed to evaluate the trends in incidence and survival outcomes of endometrial cancer (EC) across the year of diagnosis, stage, age, and histologic types. <b>Methods:</b> Women with primary EC diagnosed between 1999 and 2018 and observed until 2019 were identified from the Korea Central Cancer Registry. EC cases were identified using the International Classification of Diseases, 10^th revision. The age-standardized rates (ASRs) of incidence, annual percent changes (APCs), and survival were estimated according to age, stage, histology, and year of diagnosis. <b>Results:</b> The ASR for EC has been increasing from 2.38 per 100,000 in 1999 to 7.29 in 2018 across all histologic types (APCs of 9.82, 15.97, and 7.73 for endometrioid, serous, and clear cell, respectively, p< 0.0001). The 5-year survival showed significant difference according to histology (90.9%, 55.0%, and 68.5% for endometrioid, serous, and clear cell, respectively, p<0.0001), stage (93.4%, 77.0%, and 31.0% for localized, regional, and distant, respectively, p<0.0001), and age (93.0% for <50 years and 80.6% for ≥50 years, p<0.0001). The 5-year survival significantly improved in the group diagnosed between 2009-2018 (85.9%) than in 1999-2008 (83.3%) (p<0.0001). This trend was only observed in endometrioid (p<0.001), however, not observed in serous (p=0.5345) or clear cell histology (p=0.3468). <b>Conclusions:</b> Incidence in EC increased across the endometrioid as well as serous or clear cell histology. Survival improved in endometrioid histology over the past two decades but remained static for serous or clear cell histology. Healthcare strategies to prevent EC incidence in at-risk populations and to apply effective treatments for high-risk histology are needed.