Oral Immunonutrition Therapy to Reduce Acute Toxicity After Neoadjuvant Chemoradiotherapy Pancreatic Cancer Patients

Inclusion Criteria: * 1\. Pathologically confirmed pancreatic ductal epithelial malignant tumors; * 2\. Resectable pancreatic cancer treated with neoadjuvant chemoradiotherapy, or nonresectable locally advanced pancreatic cancer treated with neoadjuvant or radical chemoradiotherapy; * 3.Nutritional Risk Screening 2002 (NRS2002) ≥3 and Patient-Generated Subjective Global Assessment (PG-SGA) performance status B; * 4\. Age 18 years and older; * 5\. Eastern Cooperative Oncology Group (ECOG) performance status 0-1; * 6\. Expected survival time more than 3 months; * 7\. History of antineoplastic therapy; Exclusion Criteria: * 1\. Known allergy or intolerance to any component of investigational Oral Immunonutrition; * 2\. History of Oral Immunonutrition use within one month prior to enrollment; * 3\. Tumor compresses the major duodenal papilla, and /or appeared jaundice, acute pancreatitis; * 4\. Patients with contraindications for antineoplastic therapy, such as coronary heart disease, cerebral infarction, cerebral hemorrhage or other serious diseases; * 5\. Liver, kidney and blood coagulation function failure; * 6\. Patients with hemopathy; * 7\. Patients with active infections; * 8\. Patients with other primary tumor; * 9\. Patients with other medical diseases that seriously affected nutritional status; * 10.Subjects deemed by the investigator have other factors that may be ineligible for enrollment;