mFOLFIRINOX Plus Radiotherapy to Patients With CA19-9-normal Advanced Pancreatic Cancer

Inclusion Criteria: * Ability to understand and the willingness to sign a written informed consent document. * Age ≥ 18 years and ≤ 80 years. * Eastern Cooperative Oncology Group (ECOG) performance status 0-2. * Histologically or cytologically confirmed advanced pancreas adenocarcinoma. * Patients who have not received any form of anti-tumor therapy. * Baseline serum CA19-9 ≤ 37 U/mL, CEA≤ 5.2 ng/mL, and CA125 ≤ 35 U/mL. * Presence of at least of one measurable lesion in agreement to RECIST criteria. * The expected survival ≥ 3 months. * Adequate organ performance based on laboratory blood tests. * Women of childbearing potential and men must agree to use adequate contraception prior to study entry and for the duration of study participation. Exclusion Criteria: * Pregnant or nursing women. * Patients who have received any form of anti-tumor therapy. * Baseline serum CA19-9 \> 37 U/mL, CEA \> 5.2 ng/mL, or CA125 \> 35 U/mL. * The diagnosis was confirmed by pathology as non-adenocarcinoma of pancreas. * Inflammation of the digestive tract, including pancreatitis, cholecystitis, cholangitis, etc. * Severe and uncontrollable accompanying diseases that may affect protocol compliance or interfere with the interpretation of results. * Renal insufficiency or dialysis * Other serious accompanying illnesses, which, in the researcher's opinion, could seriously adversely affect the safety of the treatment. * Patients who are allergic to oxaplatin or other chemotherapy drugs. * Patients who are unwilling or unable to comply with study procedures.