The incidence of adenocarcinoma in Barrett's esophagus in an institutionalized population

To ascertain the incidence rate of adenocarcinoma in Barrett's esophagus (ACE) in a stable population of 28,000 institutionalized intellectually disabled individuals (IDI) in whom the prevalence rate of Barrett's esophagus (BE) was previously estimated in a representative sample by 24 h pH monitoring and endoscopy, and in which all cases of ACE were ascertained over a 6-year period. These IDI do not smoke or drink alcohol and are known to have exceptionally high prevalence rates of gastro-esophageal reflux disease, and consequently of BE.

A population comprising 52,038 person-years was observed and all cases of ACE were ascertained. On the basis of the representative sample, the percentage of this population with BE was estimated to be 10.8%. ACE incidence rates could then be estimated and compared with those found in a free-living BE cohort after correction for age and gender differences.

In IDI an incidence rate of ACE of 2.5/1000 person-years was found against 6.3/1000 person-years in the free-living BE cohort. However, the age distributions of the IDI and of the free-living BE cohort were very different, and after correction for this factor there was no significantly lower incidence rate of ACE in the IDI (relative risk, 0.79; P = 0.61).

This is the first reported incidence study of ACE in a stable, well-defined population. In contrast to squamous cell carcinoma, our findings suggest only a minor role for smoking and alcohol in the etiology of ACE.