Predicting Gastric Neoplasia in Patients with High-risk Endoscopic Features

Inclusion Criteria: 1. Age ≥ 45 years 2. Meets the definition of a high-risk population for gastric cancer, which includes one or more of the following: (1) Residence in a high-incidence region for gastric cancer (2) Helicobacter pylori (Hp) infection (3) History of chronic atrophic gastritis, gastric ulcer, gastric polyps, post-gastrectomy status, hypertrophic gastritis, pernicious anemia, or other precancerous gastric conditions (4) First-degree relatives of patients with gastric cancer (5) Other risk factors for gastric cancer such as high salt intake, frequent consumption of pickled foods, smoking, or heavy alcohol use 3. No gastric cancer or precancerous lesions detected on initial esophagogastroduodenoscopy, yet with endoscopic features consistent with high-risk endoscopic features. High-risk endoscopic include: (1) Active Helicobacter pylori infection (2) Atrophic gastritis (Kimura-Takemoto classification C1-O3) 4. Provision of written informed consent and agreement to comply with the follow-up requirements specified in the study protocol Exclusion Criteria: 1. Emergency esophagogastroduodenoscopy 2. History of partial or total gastrectomy 3. ASA physical status classification of 3 or higher 4. Use of oral antiplatelet or anticoagulant medications, or coagulopathy (defined as a platelet count \< 50 × 10\^9/L or INR \> 1.5) 5. Pregnancy or lactation 6. Severe cardiac, pulmonary, hepatic, or renal disease 7. Concomitant other malignant tumors or severe infectious diseases 8. Refusal to sign the informed consent form or any other condition deemed unsuitable for study participation