Assessment of intestinal metaplasia at the lesser curvature guides mapping biopsies strategy.

[AIM] Guidelines advise performing standard 4-5 sites mapping biopsies during the initial endoscopic assessment of gastric cancer risk, which increases the clinical burden. Emerging image-enhanced endoscopy (IEE) has demonstrated high diagnostic accuracy. This study aims to evaluate whether endoscopic evaluation can guide the decision to perform mapping biopsies.

[METHODS] A prospective cohort of patients underwent gastroscopy screening in a tertiary care setting, with endoscopic evaluation using white light imaging (WLI) and IEE. Mapping biopsies were performed on patients diagnosed with atrophic gastritis to assess the Operative Link on Gastritis Intestinal Metaplasia (OLGIM) staging. Multivariate logistic regression was used to assess the association of OLGIM stage III/IV. The diagnostic performance of intestinal metaplasia (IM) at the lesser curvature for identifying OLGIM stage III/IV was evaluated.

[RESULTS] OLGIM staging was completed for 648 patients with atrophic gastritis. Grade 1 and grade 2 IM of the corpus lesser curvature were significantly associated with OLGIM stage III/IV, with odds ratios of 8.17 (95% CI: 3.58-19.95) and 11.56 (95% CI: 3.66-38.94), respectively (both  < 0.001). The negative likelihood ratio (NLR) for IM at the antral lesser curvature was approximately 0.00.

[CONCLUSIONS] In regions with limited clinical resources, priority should be given to the evaluation of IM at the lesser curvature. Patients with IM at the corpus lesser curvature are suggested to undergo mapping biopsies. In the absence of IM at the antral lesser curvature, mapping biopsies may be safely omitted.