Interobserver variations for detection of atrophy and intestinal metaplasia of the stomach

Abstract

INTRODUCTION: Atrophy and intestinal metaplasia (IM) of gastric mucosa are considered pre-cancerous lesions. The Correa cascade explains the sequence to gastric cancer(1,2). Standardized histopathology is the ?gold standard? for detecting these conditions(3). Different results for the interobserver variability have been reported. AIMS & METHODS: To compare the gastric atrophy and IM readings by experts in gastrointestinal and general pathology. Gastric biopsies were obtained from 131 patients in Latvia aged 55 or above referred for upper endoscopy due to dyspeptic symptoms. H.pylori infection was present in 64%. Biopsies were sampled and analysed independently by two expert gastrointestinal pathologists and one experienced general pathologist according to the updated Sydney classification. Individually reported results were compared to the consensus results achieved by the two expert gastrointestinal pathologists re-evaluating any case of discordant grading for atrophy or IM. Cronbach's alpha was calculated to indicate interobserver reliability. Kappa statistics, comparing to the consensus was calculated; values below 0.5 represented poor, between 0.5 and 0.75 good and over 0.75 excellent agreement. RESULTS: Complete agreement between the two experts was in 76 cases (58.1%). Overall agreement compared to consensus was highest for IM detection - 91,4% in average. Low overall agreement was found for atrophy detection by the general pathologist - 38,8%. Kappa statistics see Table 1. Interobserver reliability for atrophy in antrum, incusura and corpus was 0.640, 0.762 and 0.778 and for IM ? 0.888, 0.940 and 0.926 respectively. TABLE 1: Kappa value PathologistAntrumatrophyAntrumIMIncisuraatrophyIncisuraIMCorpusatrophyCorpusIM1st0,0690,6390,0810,7800,0840,7312ndND0,7670,6430,746NDND3rd0,5310,7120,788ND0,8480,6971st- general pathologist; 2nd, 3rd- exper pathologist; ND- Kappa could not be done CONCLUSION: Good concordance of the biopsy results read according to the.