Poor interobserver agreement in the distinction of high-grade dysplasia and adenocarcinoma in pretreatment Barrett's esophagus biopsies

Am J Gastroenterol. 2008 Sep;103(9):2333-40; quiz 2341. doi: 10.1111/j.1572-0241.2008.02020.x. Epub 2008 Jul 30.

Abstract

Objective: Grading Barrett's dysplasia at the lower end of the metaplasia-dysplasia spectrum (negative, indefinite, and low-grade dysplasia) suffers from poor interobserver agreement, even among gastrointestinal pathologists. Data evaluating interobserver agreement in Barrett's mucosal biopsies with changes at the upper end of the dysplasia spectrum (high-grade dysplasia, intramucosal, and submucosal adenocarcinoma) have not been published. The accurate categorization of pretreatment biopsies drives therapeutic decision making, but if the diagnostic distinction between cancer and high-grade dysplasia in Barrett's biopsies is inconsistent, then the use of these diagnoses to make management decisions is suspect. To this end, our aim was to assess interobserver reproducibility among a group of gastrointestinal pathologists in the interpretation of preresection biopsies.

Methods: All study pathologists agreed upon the histologic criteria distinguishing four diagnostic categories, including high-grade dysplasia; high-grade dysplasia with marked distortion of glandular architecture, cannot exclude intramucosal adenocarcinoma; intramucosal adenocarcinoma; and submucosally invasive adenocarcinoma. The histologic criteria were used to independently review preresection biopsies from 163 consecutive Barrett's esophagus patients with at least high-grade dysplasia who ultimately underwent esophagectomy. Reviewers recorded the specific histologic criteria used to categorize each case and Kappa statistics were calculated to assess interobserver agreement.

Results: Using kappa statistics, the overall agreement was only fair (kappa= 0.30). Agreement for high-grade dysplasia was moderate (kappa= 0.47), while agreement for high-grade dysplasia with marked architectural distortion, cannot exclude intramucosal adenocarcinoma and intramucosal adenocarcinoma were only fair (kappa= 0.21 and 0.30, respectively) and agreement for submucosal adenocarcinoma was poor (kappa= 0.14).

Conclusions: The overall poor interobserver reproducibility among gastrointestinal pathologists who see a high volume of Barrett's cases calls into question treatment regimens based on the assumption that high-grade dysplasia, intramucosal adenocarcinoma, and submucosal adenocarcinoma can reliably be distinguished in biopsy specimens.

MeSH terms

  • Adenocarcinoma / pathology*
  • Adenocarcinoma / surgery
  • Barrett Esophagus / pathology*
  • Barrett Esophagus / surgery
  • Biopsy
  • Esophageal Neoplasms / pathology*
  • Esophageal Neoplasms / surgery
  • Humans
  • Observer Variation
  • Precancerous Conditions / pathology*
  • Precancerous Conditions / surgery