Prophylactic or Preemptive Entecavir in Patients With Gastrointestinal Cancer Who Are Inactive Hepatitis B Carriers

Inclusion Criteria

• •1. Patients with age between 18 and 75
• •2. Patient with histology-proven locally advanced unresectable or metastatic gastrointestinal cancers (colorectal cancer, gastric cancer, esophageal cancer, hepatocellular carcinoma, pancreatic cancer, and cholangiocarcinoma)
• •3. Planned to receive first-, second-, or third-line anti-tumor therapy (chemotherapy or PD-1/PD-L1 monoclonal antibody immunotherapy)
• •4. Patients with Eastern Cooperative Oncology Group performance status (ECOG) of 0-2
• •5. Patients planned for at least 4 cycles of chemotherapy or immunotherapy
• •6. Patients with at least 6 months' life expectancy from date of recruitment
• •7. Patients with chronic or past HBV infection (HBsAg-positive or HBcAb-positive), and hepatitis B is inactive
• •8. Patients with normal liver function tests including alanine aminotransferase (ALT), aspartate aminotransferase alkaline (AST), and bilirubin
• •9. Patients with negative HBV-DNA
• •10. Adequate major organ function (laboratory tests 14 days before randomization meeting requirements for anti-tumor therapy)
• •11. Patients who sign the informed consent
• •12. Patients with good compliance during chemotherapy and follow-ups.