SOX Sequential S-1 in Advanced Biliary Tract Carcinoma（BTC）and Pancreatic Cancer

Inclusion Criteria: * Written Informed consent * Male or female patients \>=18 years old * Histologically or cytologically confirmed diagnosis of adenocarcinoma * No previous treatment is allowed including chemotherapy, radiotherapy,immunotherapy or others. * In case the patient received adjuvant therapy before, enrollment is allowed if the adjuvant therapy does not contain L-OHP or S-1 and at the same time, the last day of chemotherapy is ≥180 days before screening. * Target lesion more than 1cm in diameter by enhanced CT or MRI 21 days before enrollment * The laboratory parameter meets the following criteria 7 days before enrollment * Hemoglobin ≥90g/L * Absolute neutrophil count≥1.5×10\^9/L, platelets 100×10\^9/L； * ALT and AST≤2.5 ULN(in case of the patients with liver metastasis,ALT and AST≤5.0 ULN) * ALP ≤2.5 ULN (in case of the patients with liver metastasis,≤5.0 ULN) * Total Serum bilirubin ≤1.5 ULN * Serum creatinine ≤1.0 ULN * serum albumin(ALB)≥30g/L； * can tolerate oral drug administration； * KPS ≥70 * Estimated survival ≥90 days * Women of childbearing potential must have a negative serum or urine pregnancy test within 7 days of enrollment and must be willing to use adequate methods of contraception during the study and for 30 days after last study durg administration. Exclusion Criteria: * Known sensitivity to 5-HT3 antagonist and hypersensitivity to the other treatment agents including irinotecan, cisplatin and octreotide lar * Any participati…