PD-1 Antibody Plus GEMOX as Postoperative Adjuvant Therapy in Perihilar Cholangiocarcinoma

Inclusion Criteria: 1. The patient must sign an informed consent form; 2. Age 18-75 years old, both male and female; 3. ECOG performance status score (PS score) 0 or 1 point; 4. Child-Pugh score A period; 5. Perihepatic cholangiocarcinoma with negative margins and positively metastatic lymph nodes confirmed by histopathology. Abdominal positively metastatic lymph nodes region is not limited. The 16 groups of microscopically positively metastatic lymph nodes can be included. 6. Have not received any systemic treatment within 6 months; 7. The functional indicators of important organs meet the following requirements (1)Neutrophils≥1.5\*109/L; platelets≥100\*109/L; hemoglobin≥9g/dl; serum albumin≥3g/dl; (2)Thyroid-stimulating hormone (TSH) ≤ 2 times the upper limit of normal, and T3 and T4 are in the normal range; (3)Bilirubin ≤ 1.5 times the upper limit of normal; ALT and AST ≤ 3 times the upper limit of normal; (4)Serum creatinine ≤ 1.5 times the upper limit of normal, and creatinine clearance ≥ 60ml/min (calculated by Cockcroft-Gault formula); 8. The subject has at least 1 measurable lesion (according to RECIST1.1); 8. For women who are not breastfeeding or pregnant, use contraception during treatment or 12 months after the end of treatment. Exclusion Criteria: 1. Unresectable PHC patients or postoperative diagnosis of PHC recurrence and metastasis ; 2. Past or simultaneous suffering from other malignant tumors, except for fully treated non-melanoma skin cancer, cervical carcinoma in situ, and thyroid papillary carcinoma; 3. Have used gemcitabine-based chemotherapy or have used PD-1 monoclonal antibody or PD-L1 monoclonal antibody treatment within 6 months; 4. Severe cardiopulmonary and renal dysfunction; 5. Hypertension that is difficult to control with drugs (systolic blood pressure (BP) ≥140 mmHg and/or diastolic blood pressure ≥90mmHg) (based on the average of ≥3 BP readings obtained by ≥2 measurements); 6. Abnormal coagulation function (PT\>14s), have bleeding tendency or are receiving thrombolysis or anticoagulation therapy; 7. After antiviral treatment, HBV DNA\>2000 copies/ml, HCV RNA\>1000; 8. A history of esophageal and gastric varices, significant clinically significant bleeding symptoms or a clear tendency to appear within 3 months before enrollment; 9. Active infections requiring systemic treatment; patients with active tuberculosis infection within 1 year before enrollment; a history of active tuberculosis infection more than 1 year before enrollment, and no formal anti-tuberculosis treatment or tuberculosis Still in the active period; 10. Human immunodeficiency virus (HIV, HIV1/2 antibody) positive; 11. A history of psychotropic drug abuse, alcohol or drug abuse; 12. Known to have a history of severe allergies to any monoclonal antibodies, platinum drugs, or gemcitabine; 13. Other factors judged by the investigator may affect the safety of the subjects or the compliance of the trial. Such as serious diseases (including mental illness) that require combined treatment, serious laboratory abnormalities, or other family or social factors.