Association between map-like redness and the risk of gastric cancer and high-risk precancerous lesions: a systematic review and meta-analysis

Background and aims The risk of gastric cancer (GC) following Helicobacter pylori (HP) eradication has gained increasing attention. Map-like redness (MLR) is an easily recognizable and highly specific endoscopic feature observed after eradication. We aimed to quantify the association between MLR and the risk of GC and high-risk precancerous lesions. Methods We conducted a systematic search in PubMed, Embase, the Cochrane Library, CNKI, Wanfang, CBM, and VIP databases up to April 23, 2025. The primary outcome was GC, and secondary outcomes were high-risk precancerous lesions defined as the Operative Link on Gastritis Assessment (OLGA) stage > II, Gastric Intestinal Metaplasia Assessment (OLGIM) stage > II, and Kimura–Takemoto (K-T) classification > C2. Results 14 studies were included (10 for GC, 2 for OLGA, 3 for OLGIM, and 3 for K–T classification). A significant association was observed between MLR and GC (ORs 4.38; 95% CI 3.45–5.57; I 2 = 0%). MLR was also strongly associated with high-risk precancerous lesions: OLGA stage > II (ORs 10.45; 95% CI 5.98–18.25; I 2 = 9.6%), OLGIM stage > II (ORs 10.78; 95% CI 2.02–57.60; I 2 = 94.0%), and K-T classification > C2 (ORs 4.65; 95% CI 2.62–8.25; I 2 = 19.3%). Subgroup analyses by region, study design, time direction, and H. pylori eradication status yielded consistent results (ORs range: 3.77-5.55), and leave-one-out sensitivity analyses showed stable estimates (ORs range: 4.15-4.69), confirming the robustness of the findings. Conclusion MLR is highly associated with an increased risk of GC and high-risk precancerous lesions. Systematic Review Registration https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD420251048039 , identifier CRD420251048039.