Incidence Trends and Survival in Early-Onset Esophagogastric Adenocarcinoma: A Swedish Population-Based Cohort Study

Background: Early-onset adenocarcinomas of different sites are increasing in high-income countries, data on esophagogastric ade-nocarcinoma are sparse.Methods: We performed a Swedish population-based cohort study over 1993 to 2019 to delineate differences in incidence and survival in early-onset (age 20-54 years) compared with later-onset (55-99 years) esophageal, cardia, and noncardia gastric adenocar-cinoma. Temporal incidence trends were quantified as annual percentage changes (APC) and survival differences as excess mor-tality rate ratios (EMRR) using Poisson regression and including 95% confidence intervals (CI).Results: Among 27,854 patients with esophagogastric adenocar-cinoma, 2,576 were early-onset whereof 470 were esophageal, 645 were cardia, and 1,461 were noncardia gastric. Except noncardia gastric, the male predominance was larger in early-onset compared with later-onset disease. Advanced stage and signet ring cell morphology were more common among early-onset patients. Early-onset and later-onset APC estimates were comparable and esophageal adenocarcinoma incidence increased, cardia remained stable, and noncardia gastric decreased. Early-onset patients had better survival than later-onset, which was amplified when adjusting for prognostic factors including stage [adjusted EMRR 0.73 (95% CI, 0.63-0.85) in esophageal, 0.75 (95% CI, 0.65-0.86) in cardia, and 0.67 (95% CI, 0.61-0.74) in noncardia gastric adenocarcinoma]. The early-onset survival advantage was more pronounced in local-ized stages 0 to II (all sites) and women (esophageal and noncardia gastric). Conclusions: We found no major differences in incidence trends comparing early-onset and later-onset esophagogastric adenocar-cinoma. Despite unfavorable prognostic features, early-onset eso-phagogastric adenocarcinoma survival was better than later-onset, particularly in localized stages and women.Impact: Our findings suggest delayed diagnosis in younger individuals and especially men.