Abstract / Summary
Background: The Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) systems stratify gastric cancer (GC) risk according to the extent of gastric atrophy and intestinal metaplasia. However, the clinical significance of intermediate stages remains uncertain.
Objective: To evaluate the association between OLGA/OLGIM stages and GC, with particular focus on the potential role of intermediate stages as early histological risk markers.
Methods: A systematic review and meta-analysis (PROSPERO CRD42024549931) was conducted according to PRISMA 2020 guidelines. Cohort, case-control, and cross-sectional studies reporting GC incidence or prevalence according to OLGA and/or OLGIM stage were included. Methodological quality was assessed using the Newcastle-Ottawa Scale and certainty of evidence using GRADE. Random-effects models were used to calculate pooled odds ratios (OR) and risk ratios (RR).
Results: Twenty-eight studies involving 23,390 patients were included. Methodological quality was high and certainty of evidence was moderate. Advanced OLGA III-IV and OLGIM III-IV stages were strongly associated with GC (OR 6.49 and 7.76; RR 13.26 and 4.34, respectively). Intermediate stages were also associated with GC in observational studies: OLGA II (OR 2.77; 95% CI 1.83-4.20; I2 = 71%) and OLGIM II (OR 3.63; 95% CI 2.90-4.55; I2 = 0%). However, prospective cohort studies did not demonstrate a statistically significant increase in future GC incidence for OLGA II (RR 1.20; 95% CI 0.85-1.69).
Conclusions: Intermediate OLGA and OLGIM stages may represent early histological markers associated with gastric carcinogenesis. Prospective studies are required to determine their predictive value and potential implications for surveillance strategies, particularly in high-incidence populations.