Central depression among pretreatment endoscopic features is associated with submucosal invasion in gastric fundic gland–type tumor

Introduction Fundic gland–type neoplasms show a relatively high frequency of submucosal (SM) invasion despite their small size and low-grade biological behavior. Reliable pretreatment endoscopic predictors of SM invasion, however, remain limited. This study aimed to evaluate the association between pretreatment endoscopic features and SM invasion, focusing on central depression. Methods This single-center retrospective study included fundic gland–type neoplasms treated by endoscopic submucosal dissection between January 2010 and August 2024. Only pretreatment endoscopic images obtained before biopsy were evaluated and re-assessed by multiple blinded endoscopists. Multivariable logistic regression analysis was performed using lesion size (≥5 mm vs <5 mm), central depression, and reddish coloration, with age categorized by the median as a confounder. Sensitivity analyses and an exploratory simple score analysis were conducted. Results A total of 114 lesions were analyzed, including 70 intramucosal and 44 SM-invasive lesions. Central depression was independently associated with SM invasion (odds ratio, 5.98; 95% confidence interval, 1.12–31.94; P = 0.037). Lesion size (P = 0.373), reddish coloration (P = 0.312), and age (P = 0.120) were not independently associated. In a sensitivity analysis restricted to MUC5AC-negative lesions (n = 43), central depression remained associated with SM invasion (odds ratio, 7.69; 95% confidence interval, 0.87–180.9; P = 0.104), showing a similar direction to the main analysis. Furthermore, in an exploratory simple score (0–3) incorporating lesion size, central depression, and reddish coloration, both the rate and depth of SM invasion increased stepwise with higher scores, from 31.8% for a score of 0 to 80.0% for a score of 3. Conclusion Central depression is an important pretreatment endoscopic feature independently associated with SM invasion in fundic gland–type neoplasms. Careful assessment of pretreatment endoscopic findings may aid SM invasion risk stratification and support treatment decision-making.