The Role of Extracellular DNA (ecDNA) in the Occurrence and Development of Gastric

Inclusion Criteria: 1. Age: 18-80 years old; 2. Patients who plan to undergo gastroscopy at the endoscopic center and patients who undergo surgical treatment for gastric adenocarcinoma; 3. Endoscopy doctors believe that pathological biopsy is necessary to clarify the pathological diagnosis; 4. No serious diseases or other systemic malignancies in terms of physical and mental health; 5. More than one item of non Atrophic gastritis, Atrophic gastritis, intestinal metaplasia, heterogeneous hyperplasia (low grade intraepithelial neoplasia and high grade intraepithelial neoplasia), and gastric adenocarcinoma; 6. Sign an informed consent form; Exclusion Criteria： 1. Pathological results indicate other malignant tumors of the stomach, such as stromal tumors and lymphoma; 2. The patient and their family members do not agree to use the specimen for later research projects; 3. Before gastroscopy or surgery, neoadjuvant therapy or combined with other malignant tumors; 4. Non R0 resected gastric cancer patients; 5. Pregnant or lactating women; 6. Have a history of drug abuse such as alcohol and tobacco.