Interobserver variation in assessment of gastric premalignant lesions: higher agreement for intestinal metaplasia than for atrophy.

Background: Either atrophy or intestinal metaplasia of the gastric mucosa are considered premalignant lesions. The new operative link for gastritis assessment staging system is based on the detection of atrophy, and the operative link for assessment of intestinal metaplasia staging system is based on the detection of intestinal metaplasia. Good interobserver agreement is necessary for identification of any premalignant condition.

Aims: The aim of this study was to compare the agreement between findings of gastric atrophy and intestinal metaplasia by expert and general pathologists and to analyze the possible reasons behind any possible disagreement.

Methods: Patients with dyspeptic symptoms, aged 55 years and above, without previous Helicobacter pylori eradication were enrolled and analyzed according to the updated Sydney Classification by two expert pathologists and an experienced general pathologist; the results were compared with the consensus driven by the two experts.

Results: Gastric biopsy specimens from 121 patients (91 women) were included in the analysis; the mean age of the patients was 67.4 years. H. pylori infection was present in 61.2% of patients. The level of agreement between the general pathologist and the two experts (κ-value) was 0.12, 0.46, and 0.87, respectively, for detecting atrophy in the corpus; 0.77, 0.77, and 0.65, respectively, for detecting intestinal metaplasia in the corpus; 0.06, 0.51, and 0.54, respectively, for detecting atrophy in the antrum; and 0.69, 0.85, and 0.79, respectively, for detecting metaplasia in the antrum.

Conclusion: The agreement was substantially higher for intestinal metaplasia than for atrophy. This could result in discrepancies when the operative link for gastritis assessment and operative link for assessment of intestinal metaplasia staging systems are applied and can be caused by differences in the criteria used to define atrophy.