HER2 Positive CTC in Advanced Gastric Cancer

Clinical Significance of HER2 Positive Circulating Tumor Cells(CTCs) in the Peripheral Blood of Patients With Advanced Gastric Cancer

To identify the correlation of HER2 expression in tissue and peripheral CTC. to identify the HER2 expression in CTCs with clinical prognosis in advanced/metastatic gastric cancer.

Confirm the presence of CTCs are sensitive for monitoring response to chemotherapy.

Inclusion Criteria:

• Having signed informed consent
• Age≥ 18 years old
• HER2 overexpression confirmed by IHC or ISH (IHC 3+,or IHC2+/ISH+)
• Histologically confirmed gastric adenocarcinoma
• Unresectable recurrent or metastatic disease
• Previous neo-adjuvant or adjuvant treatment for gastric cancer, if applicable, more than 6 months
• Measurable disease according to the RECIST criteria
• Karnofsky performance status ≥70
• Life expectancy of ≥3 month
• No prior radiotherapy except radiotherapy at non-target lesion of the study more than 4 weeks
• ALT and AST<2.5 times ULN (≤5 times ULN in patients with liver metastases)
• Serum albumin level ≥3.0g/dL
• Serum AKP < 2.5 times ULN
• Serum creatinine <ULN, and CCr < 60ml/min
• Bilirubin level < 1.5 ULN
• WBC>3,000/mm3, absolute neutrophil count ≥2000/mm3, platelet>100,000/mm3, Hb>9g/dl

Exclusion Criteria:

• Previous systemic therapy for metastatic gastric cancer
• Surgery (excluding diagnostic biopsy) within 4 weeks prior to study entry Contraindications of nuclear magnetic resonance image such as fitment of cardiac pacemaker , nerve stimulator, or aneurysm clip, and metallic foreign body in eye ball and so on.
• Allergic constitution or allergic history to protium biologic product or any investigating agents.
• Severe heart disease or such history as recorded congestive heart failure, uncontrolled cardiac arrhythmia, angina pectoris needing medication, cardiac valve disease, severe abnormal ECG findings, cardiac infarction , or retractable hypertension.
• Pregnancy or lactation period
• Other previous malignancy within 5 year, except non-melanoma skin cancer
• Legal incapacity