OLGA and OLGIM staging systems on the risk assessment of gastric cancer: a systematic review and meta‑analysis of prospective cohorts

Background: The Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) are established classification systems used to evaluate atrophic gastritis and intestinal metaplasia, respectively. Objectives: We evaluated the association of OLGA and OLGIM scores and the risk of gastric cancer (GC) in only prospective cohort studies. Design: Systematic review and meta-analysis. Data sources and methods: We systematically searched four databases for prospective cohorts that evaluated the use of OLGA and OLGIM staging systems in predicting the risk of GC. We primarily compared OLGA/OLGIM III–IV versus OLGA/OLGIM 0–II categories and GC events. Pooled risk ratios (RR) and absolute risk differences with their 95% confidence intervals (CIs) were calculated. Results: Eight studies were included (n = 12,526). The mean age of the patients ranged from 48.2 to 64.9 years. OLGA III–IV and OLGIM III–IV were associated with the development of GC in comparison to their 0–II categories (RR 32.31, 95% CI 9.14–114.21 and RR 12.38, 95% CI 5.75–26.65, respectively). OLGA III–IV and OLGIM III–IV were associated with an increase in the absolute risk of GC of 4% and 5%, respectively. The risk remained significant if we only included countries with high incidence of GC, and was greater if we excluded one study that included mostly patients with autoimmune gastritis. OLGA II and OLGIM II were associated with higher risk of high-grade dysplasia (HGD) and GC in comparison with OLGA 0–I and OLGIM 0–I, respectively. Conclusion: Higher stages in OLGA and OLGIM systems are associated with a significantly increased risk of developing HGD and GC, validating these scoring systems for the assessment of GC risk and the design of endoscopic surveillance programs. Trial PROSPERO registration: CRD42024565771.