Risk of Cancer Diagnosis in Patients With Eosinophilic Esophagitis Using a Nationwide Swedish Population Cohort.

Background: Eosinophilic esophagitis (EoE) is a chronic, inflammatory disease of the esophagus. Chronic inflammation has been linked to cancer development. We aimed to study the potential association between EoE and later cancer diagnosis.

Methods: In this nationwide population-based cohort study, we identified 1580 individuals with EoE diagnosed between 1990-2017 through Sweden's 28 pathology departments. Up to five general population reference individuals were matched on age and sex (n = 7533). A Cox regression analysis estimated adjusted hazard ratios (aHRs) for cancer up until December 31, 2020. To reduce potential intrafamilial confounding, we also compared EoE individuals with their unaffected siblings.

Results: During a median follow-up of 7 years, 47 individuals with EoE (3.9/1000 person-years) developed cancer versus 183 (3.2/1000 person-years) reference individuals. This corresponded to a non-significant aHR of 1.11 (95% CI = 0.80-1.53). Incidence rates were independent of budesonide and proton-pump inhibitor use. Individuals with EoE however did have an increased risk of esophageal cancer where two EoE versus one reference individual were diagnosed (aHR = 25.20; 95% CI = 2.28-278.80), and also Barrett's esophagus risk was also increased in EoE (HR = 18.18; 95% CI = 6.75-48.95). Non-esophageal gastrointestinal (GI) cancer occurred in 11 EoE versus 24 reference individuals: aHR = 2.03 (95% CI = 0.99-4.18). We found no increased risk of cancers from the skin (EoE n = 10), lung (n = 0), breast (n = 4), or blood (n = 0). Sibling analyses supported these findings.

Conclusion: We did not find any overall association between EoE and cancer development. EoE was associated with esophageal cancer, but this was very rare with wide confidence interval and few cases therefore we urge caution with generalization of these findings.