Evaluating the reporting transparency and interpretability of OLGA and OLGIM staging in gastric cancer risk stratification

BACKGROUND: OLGA and OLGIM are widely used for gastric cancer risk stratification, but published studies vary in how clearly their implementation is reported. We assessed the interpretability of OLGA/OLGIM implementation reporting, focusing on reporting transparency rather than methodological correctness, study quality, or guideline adherence. METHODS: We searched PubMed, Embase, and Cochrane CENTRAL from inception to March 20, 2026, with forward and backward citation tracking in Web of Science. Eligible studies applied OLGA and/or OLGIM and reported staging results. Two reviewers independently performed study selection and data extraction. Reporting interpretability was appraised using a prespecified framework based on two core components: biopsy sampling strategy and histological assessment with grading approach and stage derivation. RESULTS: Among 155 included studies, 75 (48.4%) had high reporting interpretability, 72 (46.5%) had moderate interpretability, and 8 (5.2%) had low interpretability. Although staging outcomes were widely reported, key details needed to understand stage generation were often incomplete, particularly biopsy sampling, grading approach, and stage derivation. These gaps limited the interpretability, reproducibility, and comparability of published OLGA/OLGIM evidence. CONCLUSIONS: Studies applying OLGA and OLGIM show substantial variability in implementation reporting. Limited interpretability often reflects incomplete reporting rather than demonstrable deficiencies in underlying methods. More consistent and transparent reporting may improve reproducibility, facilitate cross-study comparison, and support clinical translation.