Gastric cancer (GC) is one of the most common and lethal cancers worldwide, especially in China, and the median overall survival for patients with advanced, metastatic GC remains only about 1 year. Several molecular profiling studies have demonstrated that a proportion of gastric cancer harbour actionable molecular alterations which shows a predictive benefit from a specific therapy (in any cancer type). In the current study, the efficacy of precision treatment for gastric cancer guided by multidimensional molecular biology profiling will be observed. The analysis focused on the overall survival outcomes for patients whose tumours harboured actionable molecular alterations and who received appropriately matched therapy.

Inclusion Criteria:

1. Male or female. Age: 18-80 years.
2. Histologically confirmed adenocarcinoma of the stomach or gastro-esophageal junction with inoperable locally advanced or recurrent and/or metastatic disease, not amenable to curative therapy.
3. Measurable disease, according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, assessed using imaging techniques (CT or MRI).
4. Multidimensional molecular biology profiling has been conducted using tumor or blood sample.
5. ECOG Performance status 0-1.
6. Life expectancy of at least 3 months.
7. Signed informed consent.

Exclusion Criteria:

1. The quality of NGS reports does not fit the requirement.
2. History of documented congestive heart failure; angina pectoris requiring medication; evidence of transmural myocardial infarction on ECG; poorly controlled hypertension (systolic BP > 180 mmHg or diastolic BP > 100 mmHg); clinically significant valvular heart disease; or high risk uncontrollable arrhythmias.
3. Baseline LVEF < 50% (measured by echocardiography or MUGA).
4. Patients with dyspnea at rest due to complications of advanced malignancy or other disease, or who require supportive oxygen therapy.
5. Patients receiving chronic or high dose corticosteroid therapy. (Inhaled steroids and short courses of oral steroids for anti-emesis or as an appetite stimulant are allowed).
6. Known dihydropyrimidine dehydrogenase (DPD) deficiency.
7. History or clinical evidence of brain metastases.
8. Serious uncontrolled systemic intercurrent illness, e.g. infections or poorly controlled diabetes.
9. Positive serum pregnancy test in women of childbearing potential.
10. Subjects with reproductive potential not willing to use an effective method of contraception.
11. Major surgery within 4 weeks of start of study treatment, without complete recovery.
12. Patients with known active infection with HIV, HBV, or HCV.

Patients with biopsy-confirmed gastric cancer at stage IV who conducted molecular testing are included.