Clinical Research Directory

Inclusion Criteria * Age between 18 and 75 years. * Scheduled for upper gastrointestinal endoscopy for the assessment of gastric diseases, including gastric cancer (stage I-IV), gastric precancerous lesions, and other benign gastric disorders. * No previous treatment for the current gastric disease prior to blood collection, including surgery, chemotherapy, radiotherapy, immunotherapy and other anti-tumor therapies. * Able and willing to participate and provide written informed consent. Exclusion Criteria * Receiving therapeutic gastroscopy or endoscopic resection for gastric lesions diagnosed in other institutions. * Presence of conditions that hinder complete gastric endoscopic visualization and reliable lesion evaluation, such as gastric retention and severe esophageal stenosis. * History of other malignant tumors, prior anti-tumor treatment, or partial/total gastrectomy. * Severe hemodynamic instability, malignant arrhythmia, unstable cardiovascular diseases, or recent major surgery. * Hematological disorders, recent blood transfusion history, severe active infection, chronic infectious diseases (e.g., HIV), or severe systemic inflammation affecting blood cell composition. * Pregnant or breastfeeding women. * Enrolled in other concurrent clinical trials that may affect the current study results. * Refusal to sign informed consent or failure to comply with study procedures.