Trends in Esophageal Adenocarcinoma and Esophageal Squamous Cell Carcinoma Incidence in the United States from 1992 to 2019

SIMPLE SUMMARY: The incidence of esophageal cancer overall has increased in the United States, driven by increasing rates of esophageal adenocarcinoma (EAC). However, whether rates of EAC are still rising is unclear. We examined trends in esophageal cancer overall and within important sub-groups of the population. We found that esophageal squamous cell carcinoma (ESCC) rates have been steadily declining, while EAC rates rose rapidly before stabilizing in 2000. The trend of decreasing incidence of ESCC was observed almost uniformly by age group, sex, and race/ethnicity, while trends in EAC rates varied across these sub-groups. A cohort effect for EAC was observed among people born during 1950, but EAC rates were stable across successive generations born between 1950 and 1985. Given the continued rising rates of known EAC risk factors, including obesity and gastroesophageal reflux disease, there is a need to continue monitoring trends for changes in incidence rates. ABSTRACT: Background: Esophageal cancer (EC) incidence rates overall have declined in recent decades; however, the two main subtypes, esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), show divergent secular trends. Methods: Age-adjusted EC incidence rates were calculated using data from the Surveillance Epidemiology and End Results (SEER) 12 Program. We examined secular trends from 1992 to 2019 overall and by age group, sex, race/ethnicity, tumor location, and SEER registry. Joinpoint regression was used to compute annual percent changes (APC) and average annual percent changes (AAPC). We used age-period-cohort models to examine the potential impact of period and birth cohort effects on trends. Results: Between 1992 and 2019, overall EC incidence rates declined by 0.54% annually (95% confidence interval [CI]: −0.75%, −0.33%). While ESCC rates declined linearly throughout the study period (AAPC = −2.85; 95%CI: −3.05%, −2.65%), EAC rates increased by over 5% annually from 1992 to 2000 (APC = 5.17; 95%CI: 3.28%, 7.10%), before stabilizing from 2000 to 2019 (APC = 0.22; 95%CI: −0.16%, 0.60%). Trends in ESCC and EAC varied by age group, sex, and race/ethnicity. Relative to ESCC rates among cohorts born circa 1950, the rates were 81% lower in cohorts born circa 1985 (rate ratio, 0.19; 95%CI: 0.04, 0.96). For EAC, rates have remained stable across successive birth cohorts since 1950. Conclusions: We observed linear declines in EC rates overall and for ESCC across age, sex, and race/ethnicity subgroups, but an inconsistent pattern for EAC. The trends in EAC cohorts born after 1955 were stable and suggest that EAC rates may have peaked in the U.S.