Maintenance Chemotherapy With S-1 vs. Observation After Adjuvant Therapy for Resected Pancreatic Cancer With High Risk of Recurrence/Metastasis

Exclusion Criteria

• •1. Pancreatic cancer originating from non-pancreatic ductal epithelium, including pancreatic neuroendocrine tumors, pancreatic acinar cell carcinoma, pancreatoblastoma, and solid-pseudopapillary tumor;
• •2. Incomplete macroscopic resection (R2 resection);
• •3. Presence of distant metastasis (including malignant ascites and pleural effusion, peritoneal metastasis) or locally recurrent pancreatic cancer;
• •4. CA19-9 \> 180 U/mL within 21 days before enrollment;
• •5. Severe liver dysfunction (AST/ALT \> 3.5 times the upper limit of normal, alkaline phosphatase \> 6 times the upper limit of normal), with liver drainage;
• •6. Known peripheral neuropathy (CTCAE ≥ Grade 2);
• •7. Participation in another clinical trial of cytotoxic drugs, targeted therapies, immunotherapies, etc., within the past 4 weeks, or received systemic chemotherapy, radiotherapy, or biological therapy within the past 4 weeks;
• •8. Concurrent or metachronous cancers with disease-free survival ≥ 5 years (excluding pancreatic cancer), except for cancers that have been cured or can be potentially cured with local excision (e.g., esophageal cancer, gastric cancer, colorectal cancer, cervical cancer, non-melanoma skin cancer, bladder cancer);
• •9. Factors that significantly affect oral drug absorption, such as difficulty swallowing, chronic diarrhea, or gastrointestinal obstruction; uncontrolled Crohn's disease or ulcerative colitis;
• •10. Clinically symptomatic serous effusions (including pleural effusion, ascites, pericardial effusion) requiring symptomatic treatment;
• •11. Pregnant or breastfeeding women; patients of childbearing potential unwilling or unable to take effective contraceptive measures;
• •12. Known allergy to the investigational drug, the class of the investigational drug, or its components;
• •13. Need for systemic corticosteroid treatment (except for local steroid pre-treatment);
• •14. History of interstitial lung disease (including interstitial pneumonia, pulmonary fibrosis, etc.) or CT findings of interstitial lung disease;
• •15. Active local or systemic infection requiring treatment;
• •16. Heart failure NYHA classification ≥ II or severe heart disease;
• •17. Known HIV infection or history of acquired immunodeficiency syndrome (AIDS) or active hepatitis B or C;
• •18. Toxicity not recovered (CTCAE \> Grade 1) or previous anticancer surgery not fully recovered;
• •19. Patients deemed unsuitable for this study by the investigator.