How useful is histologic confirmation of intestinal metaplasia in patients with long-segment Barrett's esophagus?

Abstract

BACKGROUND: Controversy exists regarding the usefulness of histologic confirmation of intestinal metaplasia in patients with long-segment Barrett's esophagus (LSBE).

OBJECTIVES: To determine the frequency of intestinal metaplasia in patients with LSBE and to establish an optimal biopsy protocol to detect intestinal metaplasia in these patients.

DESIGN AND INTERVENTION: This retrospective, single-center study included consecutive patients with LSBE (defined as ≥1 cm of columnar-lined esophagus). Exclusion criteria included previous surgical repair of the lower esophageal sphincter. Patients were arbitrarily allocated to one of two endoscopic biopsy procedures: endoscopy with 1–4 biopsies taken, or endoscopy with >4 biopsies taken. The number of biopsies taken in the >4 biopsies group was influenced by clinician judgment. All biopsy specimens were histologically assessed using hematoxylin and eosin staining. At least three gastrointestinal pathologists examined each specimen to determine the mucosa type (intestinal metaplasia, cardiac type, fundic type, glandular not otherwise specified, or squamous). Intestinal metaplasia was diagnosed by the presence of goblet cells. Further histologic assessment with standard alcian blue-periodic acid–Schiff staining was performed in a subset of patients who had >6 biopsies taken during endoscopy. At least two pathologists assessed these specimens. Patients were stratified by the number of biopsies taken per endoscopy: 1–4, 5–8, 9–12, 13–16 and >16.

OUTCOME MEASURES: The main outcome measures were the detection of intestinal metaplasia, and the frequency of intestinal metaplasia detected according to the number of biopsies taken.

RESULTS: In total, 125 patients (mean age 65 years [range 41–85 years]) were included, in whom 296 endoscopies were performed and 1,646 biopsies were taken. Mean follow-up was 25 months. The mean length of a Barrett's esophagus segment was 4 cm (range 1–11 cm). Intestinal metaplasia was present in 80 patients (64%); 150 endoscopies (51%) revealed intestinal metaplasia and 557 biopsies (34%) contained foci of intestinal metaplasia. The mean percentage of patients in whom intestinal dysplasia was detected was significantly greater in the group that had 5–8 biopsies taken per endoscopy than the group that had 1–4 biopsies taken per endoscopy: 67.9% (95% CI 64–71.8%) and 34.6% (95% CI 32–37.6%), respectively; P <0.001. There was no significant difference in the mean percentage of intestinal metaplasia detected between patients who had 5–8 biopsies taken per endoscopy, and those who had 9–12, and 13–16 biopsies taken per endoscopy; the diagnostic yield of intestinal metaplasia was 100% if >16 biopsies were taken per endoscopy. Standard alcian blue-periodic acid–Schiff staining resulted in a change in diagnosis for 5 of 92 patients (5.4%) who underwent this assessment. Increasing age was associated with a significant reduction in the risk of detecting intestinal metaplasia.

CONCLUSION: A minimum of eight random biopsies are required to be taken per endoscopy to diagnose intestinal metaplasia in patients with LSBE.