The research group, based in the Divisions of Epidemiology and Public Health, and Primary Care, were interested in determining the validity of the suggestion that gastro-esophageal reflux disease (GERD) is a more important determinant of risk of developing esophageal adenocarcinoma than is Barrett's esophagus.
It is already known that patients with Barrett's esophagus develop esophageal cancer more frequently than the general population.
The researchers therefore examined the risk of esophageal cancer in patients with Barrett's and with GERD compared with the general population in a community based cohort study.
A total of 1677 patients with Barrett's, 6392 with esophagitis and 6328 with simple reflux were included in the study.
As a reference cohort 13416 subjects were also selected from the General Practice Research Database (GPRD).
| Patients with Barrett's esophagus:|
10 times increased risk of esophageal cancer30 times increased risk of esophageal adenocarcinoma
Each cohort of patients (esophagitis, simple reflux and GPRD) were matched to the Barrett's cohort by general practitioner practice, age and sex.
Using Cox's regression analysis, the relative risks for esophageal cancer were calculated, with standardized incidence ratio methodology used to estimate the relative risks for esophageal adenocarcinoma.
In total, 137 esophageal cancers were identified, of which 94 prevalent cases were excluded.
The hazard ratios for oesophageal cancer were 10.6 (5.1–22.0), 2.2 (0.9–5.2), and 1.7 (0.7–4.5) in the Barrett’s, esophagitis, and reflux cohorts compared with the reference cohort, respectively.
The corresponding relative risks for oesophageal adenocarcinoma were 29.8 (9.6–106), 4.5 (1.04–19.6), and 3.1 (0.6–14.2).
These results show that Barrett's esophagus increases the risk of esophageal cancer approximately 10 times compared with the general population.
In the case of esophageal adenocarcinoma the risk is increased approximately 30 times.
However, there is only a modestly increased risk of esophageal cancer in patients with reflux who have no record of Barrett's esophagus.
This leads the report authors to conclude that their findings do not support the suggestion that gastro-esophageal reflux disease itself predisposes to cancer.