Aims: To compare detection of Barrett's dysplasia and adenocarcinoma by systematic versus nonsystematic surveillance biopsy protocols.
Methods: Upper GI consultation and open-access endoscopy are provided jointly at Glasgow Royal Infirmary by medical and surgical teams. The surgical team adopted annual systematic four-quadrant biopsy Barrett's surveillance in 1995. The medical team continued annual Barrett's surveillance with nonsystematic biopsy until 2004. We compare detection of Barrett's dysplasia and esophageal adenocarcinoma in unselected patients by these two biopsy strategies over 10 yr. All patients had > or = 3 cm Barrett's esophagus and histological proof of intestinal metaplasia. Patients referred for dysplasia management or with prevalent adenocarcinoma were excluded. Cohort A (N = 180) had four-quadrant biopsy every 2 cm while cohort B (N = 182) had nonsystematic biopsies.
Results: Cohort A versus cohort B: Median number of biopsies per endoscopy: 16 versus 4. Prevalence of low-grade dysplasia (per patient): 18.9% versus 1.6% (P << 0.001). Prevalence of high-grade dysplasia: 2.8% versus 0% (P = 0.03). Incidence of low-grade dysplasia: 2.2% versus 6.6% (NS). Incidence of high-grade dysplasia: 2.8% versus 0% (P = 0.03). Nine cohort A patients (total 5%, 1.4% per patient-year) were treated for HGD (eight endoscopically, one by esophagectomy). Two had intramucosal adenocarcinoma. No cohort A patient developed advanced cancer but three cohort B patients developed and died of invasive Barrett's adenocarcinoma (0.6% per patient-year).
Conclusions: Patient age, gender, Barrett's segment length, and follow-up were similar (though not identical) in both cohorts, but confounding seems unlikely to account for a 13-fold difference in detection of prevalent dysplasia between the two groups. Our data support the hypothesis that systematic four-quadrant biopsy is considerably more effective than nonsystematic biopsy sampling in detecting Barrett's dysplasia and early adenocarcinoma. Greater biopsy numbers and the systematic pattern of biopsy taking may both contribute to this greater effectiveness.