Gastric Cancer Risk in Patients with Intestinal Metaplasia: Long-Term Outcomes from a Large Single-Center Cohort in...

Background/Objectives: Gastric intestinal metaplasia (GIM) is a recognized premalignant condition for gastric cancer (GC), but long-term outcomes and predictors of progression remain incompletely understood. This study aimed to evaluate the progression of GIM and identify factors associated with malignant transformation. Methods: In this retrospective single-center study, 1204 adult patients with histologically confirmed GIM and at least 12 months of follow-up after esophagogastroduodenoscopy (EGD) were analyzed. Clinical and pathological variables, including GIM extent, Helicobacter pylori status, family history of GC, demographic factors, and residence in endemic regions, were assessed. Patients were stratified into high- and low-risk groups according to established criteria, and progression to GC or other neoplasms was recorded. Results: During a mean follow-up of 38.6 months, 49.1% of patients had no detectable GIM at the end of follow-up, 48.7% remained unchanged, and 2.2% showed disease progression. Among progressed cases, adenocarcinoma accounted for 66.7%, dysplasia for 29.6%, and SCC for 3.7%. Progression was significantly more common among males, older patients, and those with antrum + corpus involvement. The overall progression rate from GIM to adenocarcinoma was 1.5% (approximately 0.45% per patient-year). No significant difference in progression or survival was observed between high- and low-risk groups. Conclusions: The long-term malignant transformation rate of GIM is low. Male sex and extensive gastric involvement were associated with higher progression rates, while H. pylori was not predictive of malignant transformation. These findings support individualized surveillance strategies for patients with GIM, while routine surveillance of antrum-limited GIM may provide minimal benefit but increase healthcare burden.