Aims: Previous studies have shown a positive association between colorectal cancer and Barrett's oesophagus, but this association is disputed. To date, no population-based studies have examined the incidence of this cancer in patients with Barrett's oesophagus; we carried out such a study.
Methods: A population-based cohort of patients with Barrett's oesophagus was constructed by examining pathology reports of all oesophageal biopsies in Northern Ireland between 1993 and 1999. Cases of colorectal cancer were identified and standardised incidence ratios for colorectal cancer were calculated.
Results: 2,969 patients with Barrett's oesophagus were followed up for a total of 14,014 years (mean 4.7 years). Colorectal cancer was diagnosed in 39 patients and in 22 of these patients the cancer was diagnosed at least six months after the diagnosis of Barrett's oesophagus. The standardised incidence ratio (95% Confidence Interval) for colorectal cancer, occurring at least 6 months after entry into the cohort, after at least 3 months, after at least 1 month, and at any time after the diagnosis of Barrett's oesophagus, were: 0.82 (0.48–1.17), 0.94 (0.57–1.30), 1.09 (0.69–1.48) and 1.46 (1.00–1.92), respectively.
Conclusions: The incidence of colorectal cancer was not elevated in patients with Barrett's oesophagus. Diagnostic bias may explain why previous studies have found an association.
