Apatinib Combined With S-1 in the Second-line Treatment of Advanced Pancreatic Cancer

Inclusion criteria:

* 18-70 years old;
* ECOG score: 0-2;
* Have confirmed metastatic or locally advanced unresectable pancreatic cancer;
* At least one measurable lesion according to the RECIST1.1 standard;
* First-line chemotherapy drugs do not include S-1 or fluorouracil drugs;
* Main organ functions meet the following standards:

  * Baseline blood routine (the inspection standard should meet the requirements of no blood transfusion and blood products within 14 days, no use of G-CSF and other hematopoietic stimulant correction) :

    * Hemoglobin\>80g/L
    * The absolute neutrophil count (ANC) 1.5 x 109 / L;
    * Blood platelet (PLT)\> 90 x 109 / L;
  * Baseline biochemical test shall meet the following standards:

    * T BIL \< 1.5\*ULN.
    * A LT and AST\<2.5\*ULN, and in patients with liver metastasis \< 5\*ULN;
    * Cr≤1.5\*ULN.
    * Albumin is greater than or equal to 30g/L;
* Women of child-bearing age must already have access to reliable contraception. Pregnancy tests (serum or urine) were performed within 7 days prior to enrollment and the results were negative, and a reliable method of contraception was preferred 8 weeks after the trial period and the last drug administration;
* Subjects will voluntarily join the study and sign the informed consent.

Exclusion criteria:

* Clearly allergic to apatinib, S-1 or their excipients;
* There are various factors affecting oral drugs (including dysphagia, chronic diarrhea, intestinal obstruction, etc.);
* Serious heart diseases in the last six months, including :

  * angina;
  * myocardial infarction;
  * heart failure;
  * interphase of QTc \>450ms;
  * any other heart diseases that were judged as unsuitable for the study;
* Combined with uncontrollable hypertension after drug treatment (systolic blood pressure \>140mmHg, diastolic blood pressure \>90mmHg);
* Complicated with other serious medical diseases, including cerebrovascular disease, uncontrolled infection, active peptic ulcer, intestinal obstruction, etc.;
* Metastasis of tumor central nervous system;
* Women during pregnancy and lactation;
* The patient has been diagnosed with other tumors in the past five years, except for the following situations: B. Cured basal cell carcinoma of the skin and cured orthotopic carcinoma of the cervix;
* The time from the last chemotherapy is shorter than 4 weeks or 5 half-life (the time taken is older), and the time from the last radiotherapy is shorter than 4 weeks;
* Use the experimental drug within 28 days before enrollment;
* Patients with grade 2 or above toxicity caused by the use of anti-tumor drugs before enrollment;
* Have mental disorders or a history of substance abuse;
* Other circumstances that the investigator deems inappropriate to participate in the study;