Incidence trends of esophageal squamous cell and adenocarcinoma in Finland in 2000–2021

Background and purpose: Esophageal cancer (EC) histological subtypes have contrasting incidence trends according to previous studies. In high-income countries, the incidence of esophageal squamous cell carcinoma (SCC) has decreased, while the incidence of esophageal adenocarcinoma (AC) has increased. This descriptive registry-based study evaluates incidence trends by EC subtype in Finland during 2000–2021. Material and methods: Data on all EC cases by histological subtype, sex and 10-year age group diagnosed over the period 2000–2021 was obtained from the Finnish Cancer Registry. In total, 6,482 cases (2,604 AC, 2,979 SCC) were observed. Time trends by histology, sex and age group were evaluated with Poisson regression and joinpoint regression. Results: EC incidence in men increased by an annual percentage change (APC) of 1.3 (95% confidence intervals [CI] 0.8–1.8) while no significant increase was observed in women with APC of -0.1, 95% CI -0.8–0.6). Incidence of AC in men increased with APC of 3.5 (95% CI 2.7–4.2) and by 2.0 (95% CI 0.4–3.6) in women. No consistent trends were observed in SCC incidence although in joinpoint regression, from 2000 to 2006 SCC incidence decreased in men by APC of -6.5 (95% CI -20.3 to -1.1). From 2006 to 2021, rates plateaued with APC of 0.9 (95% CI -0.4 to 7.2). No other joinpoints were identified. Interpretation: EC incidence increased in Finland during 2000–2021 due to an increase in AC. Incidence of AC increased more than threefold in men, with a lesser increase in women. SCC incidence declined until 2006 and plateaued thereafter.