Survival With Olanzapine in Patients With Locally Advanced or Metastatic Upper Gastrointestinal and Lung Cancer

Inclusion Criteria: 1. Aged 18 years or older; 2. Eastern Cooperative Oncology Group performance status of 0-3; 3. Stage III or IV inoperable or metastatic gastric cancer, esophageal cancer, hepato-pancreaticobiliary cancer and lung cancer confirmed by histology or cytology; 4. Subjected to palliative systemic chemotherapy, regardless of first-line or second-line treatment; 5. Expected survival ≥ 3 months; 6. The patient is eligible for oral administration without dietary restrictions; 7. Exhibits a favorable adherence to treatment and follow-up, demonstrates compliance with the research protocol, and willingly signs the informed consent form. Exclusion Criteria: 1. Weight loss and gain may be attributed to alternative factors, such as edema or ascites; 2. Suffers from mental disorders or is under the medication of any antipsychotic or antidepressant drugs; 3. History of central nervous system disorders (such as brain metastasis, epilepsy; 4. Patients undergoing sustained administration of sedative medications or long-term hormonal therapy, individuals with chronic alcoholism, or those with substance dependence on medications; 5. Prohibition of Olanzapine Intake for Contraindicated Individuals; 6. History of clozapine-induced agranulocytosis because patients will be at increased risk for neutropenia with Olanzapine; 7. Uncontrolled diabetes mellitus and Uncontrolled seizure disorder; 8. Pregnant and Nursing women; 9. Exclusion criteria include active participation in another interventional clinical trial, ongoing involvement in an observational (noninterventional) clinical trial, or being in the survival follow-up phase of an interventional clinical trial; 10. Researchers posit that any condition deemed potentially harmful to the subjects or that might prevent subjects from meeting or adhering to the research requirements shall not be permissible for inclusion in this study.