Eosinophilic Oesophagitis and Incidence of Gastrointestinal Cancer: A Population-Based Cohort Study

Evidence concerning gastrointestinal cancer risk after eosinophilic oesophagitis (EoE) diagnosis is limited.

To examine the association between EoE and incident gastrointestinal cancer in a population-based cohort.

Using nationwide Danish health registries, we identified all patients diagnosed with EoE between 1997 and 2024, using a validated algorithm. We computed standardised incidence ratios (SIRs) for gastrointestinal cancers overall and site-specific cancers compared with the general population. To distinguish short-term diagnostic activity from longer-term risk, we stratified analyses by < 1 and ≥ 1 year after EoE diagnosis. Secondary analyses examined oesophageal cancer incidence among EoE patients with coexisting Barrett's oesophagus (BE).

Among 9115 EoE patients, 170 developed gastrointestinal cancers. During the first year after EoE diagnosis, the SIR was 2.83 (95% confidence interval: 2.10-3.74). Beyond 1 year, the overall SIR attenuated (1.03 [0.85-1.23]) but remained elevated for oesophageal cancer (2.40 [1.42-3.79]) and hepatocellular carcinoma (2.05 [0.98-3.77]). Among patients who developed oesophageal cancer ≥ 1 year after EoE diagnosis (n = 18), most had prior BE. The SIR for oesophageal cancer was 5.44 (2.90-9.31) among patients with both EoE and BE and 4.84 (4.36-5.37) among patients with BE alone. SIR for patients with EoE alone could not be reported due to the low number of cancer cases.

One year after EoE diagnosis, oesophageal cancer and hepatocellular carcinoma rates remained elevated. Most oesophageal cancers occurred in patients with prior BE, suggesting that the association between EoE and oesophageal cancer may be mediated largely through BE.