A Population-based, Multicenter Cohort Study of Combined Screening for Gastrointestinal Tumors

Inclusion Criteria: * 1\. Subjects were 45 to 70 years old when enrolled 2. Willing and able to sign informed consent Exclusion Criteria: * 1\. History of any type of malignancy 2. Previous resection of esophagus, stomach or colorectal 3. Received gastrointestinal endoscopy such as colonoscopy and gastroscopy in recent 5 years 4. Have received fecal occult blood test and fecal DNA test in the past 1 year. 5. Contraindications to endoscopy. 6. Warning symptoms of digestive tract tumors, including: 1. Difficulty swallowing, choking or halting feeling when eating recently 2. Recent esophageal foreign body sensation or swallowing pain 3. Recent long-term loss of appetite and appetite 4. Recent and prolonged symptoms of indigestion (including acid reflux, heartburn, abdominal grumbling, burping, nausea or premature satiety, etc.) 5. Recent symptoms of abdominal mass, abdominal pain, vomiting or hematemesis 6. It was medically diagnosed as iron deficiency anemia 7. Recent changes in hematochezia, black stool or stool character and frequency 8. Recent symptoms of perianal discomfort (including soreness, itching, lumps, prolapse or other discomfort) 9. Unexplained weight loss (more than 10% of base body weight) in the past 6 months Step 7 Get pregnant 8. There are other serious comorbiditions that reduce screening benefits (including severe lung disease, advanced kidney disease, advanced liver disease, severe heart failure, etc.)