Metronomic Chemotherapy With Capecitabine for Pancreatic Cancer

Inclusion Criteria: 1. Histologically confirmed pancreatic invasive ductal adenocarcinoma. 2. The patient underwent surgery for pancreatic tumor resection, and no gross residual lesions were found postoperatively (R2). 3. Stage II/III pancreatic cancer was determined according to AJCC/UICC TNM stage eighth. 4. At least 6 cycles of gemcitabine plus capecitabine chemotherapy have been completed. 5. Age 18-70 years old, gender not limited. 6. ECOG performance score is 0 or 1. 7. Without dysphagia, able to tolerate oral administration. 8. No relevant clinical or imaging evidence of recurrence or metastasis showing within the 28 days before random. 9. Chemotherapy with capecitabine combined with gemcitabine regimen was given within 12 weeks after surgery, and last chemotherapy to random time ≤ 6 weeks. 10. Adequate bone marrow, liver, and kidney function in measurements taken within 7 days before registration ： 11. Hemoglobin ≥ 90 g/L, Platelet count ≥ 100×109/L, Absolute granulocyte count ≥ 1.5×109/L. i. Note: patients should not receive blood transfusion or growth factor support within 14 days before collection of blood samples. 12. Serum creatinine≤ 1.5 ULN, and calculated creatinine clearance of ≥ 60 mL/min/1.73m2. 13. AST and ALT ≤ 2.5 X ULN, serum total bilirubin ≤ 1.5 X ULN (Patients with Gilbert syndrome with total bilirubin≤ 3 X ULN can be enrolled). 14. INR or PT ≤ 1.5×ULN，unless the patient is receiving anticoagulant therapy and the PT value is within the expected therapeutic range of the anticoagulant. 15. Electrocardiogram and cardiac function were not contraindicated in chemotherapy. 16. Women should have a negative pregnancy test, and all the patients have no planning within 3 years and should take contraceptive measures during treatment. 17. Informed consent form signed. Exclusion Criteria: 1. Other pathological types of pancreatic malignancies (e.g. neuroendocrine carcinoma, large cell carcinoma, signet ring cell carcinoma, etc.). 2. With distant metastasis or malignant pleural effusion. 3. Pregnant and breast-feeding women. 4. Unable to oral medication. 5. Previous or concurrent malignancies, excluding curatively treated in situ carcinoma of the cervix or non-melanoma skin cancer, unless at least 5 years have elapsed since last treatment and the patient is considered cured. 6. A history of transient ischemic attack, cerebrovascular accident, thrombosis, or thromboembolism (pulmonary embolism or deep venous thrombosis) within 180 days before randomization. 7. Any of the following uncontrolled or severe cardiovascular disease history: 8. Myocardial infarction occurred 180 days before randomization. 9. Uncontrolled angina occurred within 180 days before randomization. 10. Heart failure of class III or IV (according to New York Heart Association functional classification). 11. Uncontrolled hypertension after appropriate treatment (e.g. Systolic blood pressure ≥150mmHg or diastolic blood pressure ≥90mmHg for 24h or longer). 12. Arrhythmias that require treatment, including pacemakers. 13. Serious drug allergy. 14. Uncontrolled diabetes or systemic infection. 15. Known dihydro pyrimidine dehydrogenase (DPD) deficiency. 16. Any other reasons the investigator considers the patient should not participate in the study. 17. Without personal freedom and independent civil capacity. 18. Already enrolled into other clinical trials.