The staging of gastritis with the OLGA system by using intestinal metaplasia as an accurate alternative for atrophic gastritis

Abstract

Background: The OLGA (operative link on gastritis assessment) staging system is based on severity of atrophic gastritis (AG). AG remains a difficult histopathologic diagnosis with low interobserver agreement, whereas intestinal metaplasia (IM) is associated with high interobserver agreement.

Objective: The aim of this study was to evaluate whether a staging system based on IM is preferable to estimate gastric cancer risk.

Design and setting: Prospective multicenter study.

Patients: A total of 125 patients previously diagnosed with gastric IM or dysplasia.

Interventions: Surveillance endoscopy with extensive biopsy sampling.

Main outcome measurements: Three pathologists graded biopsy specimens according to the Sydney classification. Interobserver agreement was analyzed by kappa statistics. In the OLGA, AG was replaced by IM, creating the OLGIM.

Results: Interobserver agreement was fair for dysplasia (kappa = 0.4), substantial for AG (kappa = 0.6), almost perfect for IM (kappa = 0.9), and improved for all stages of OLGIM compared with OLGA. Overall, 84 (67%) and 79 (63%) patients were classified as stage I-IV according to OLGA and OLGIM, respectively. Of the dysplasia patients, 5 (71%) and 6 (86%) clustered in stage III-IV of OLGA and OLGIM, respectively.

Limitation: Prospective studies should confirm the correlation between gastric cancer risk and OLGIM stages.

Conclusion: Replacement of AG by IM in the staging of gastritis considerably increases interobserver agreement. The correlation with the severity of gastritis remains at least as strong. Therefore, the OLGIM may be preferred over the OLGA for the prediction of gastric cancer risk in patients with premalignant lesions.