A Clinical Trial Evaluating the Efficacy and Safety of Dasatinib in Refractory Metastatic GIST

Inclusion Criteria: * Histologically confirmed recurrent/metastatic gastrointestinal stromal tumor (GIST). Immunohistochemically, the detection KIT and/or DOG-1 are/is positive * Patients must have measurable disease meeting the requirement of RECIST 1.1 * Received the gene mutation detection of c - kit/PDGFRA * Subjects with mutation in exon 11, in exon 9 and wild type c-kit/PDGFRA have failed to imatinib and sunitinib * Subjects with primary mutation in exon 17 or 18 have failed to imatinib * Subjects with primary mutation in exon 11 and secondary mutation in exon 17 or 18 have failed to imatinib * Subjects with mutation in exon 18 of PDGFRA,have received TKI or not * Eastern Cooperative Oncology Group (ECOG) performance status = 0-2 * Expected OS ≥3 months * Ability to understand and the willingness to sign a written informed consent document * Subject will comply with the study procedures and therapy Exclusion Criteria: * Local or metastatic GIST is resectable * Unable to receive the gene mutation detection of c-kit (c-kitproto-oncogeneprotein)/PDGFRA * AST and/or ALT \> 2.5 times ULN, or Bilirubin \>1.5 times upper limit of normal (ULN) * Neutrophil count \< 1.5 x 10\^9/L, or Platelet count \<75 x 10\^9/L, or Hemoglobin\<90g/L * Cr \>1.5×ULN * Other malignancy within the past 5 years except for adequately treated carcinoma in situ of the cervix or cutaneous basal cell carcinoma * Known brain metastasis, spinal cord compression, carcinomatous meningitis, or cerebral or soft meningeal disease through CT or MRI during screening stage * Within the past 5 years, subjects have one of the following disease: myocardial infarction, serious/instable angina pectoris, symptomatic congestive heart failure or cerebrovascular accident from coronary/peripheral artery bypass grafting * Known human immunodeficiency virus positivity * Joining in other trail * Women who are pregnant or lactating; No contraception for subject during childbearing period * Subject with other serious acute and chronic physical or mental problems, or laboratory abnormality, will increase the risks associated with trail or drug. It will also interference the judgment of the results. In the judgment of the investigator, subject is inadequate to participant the study