Efficacy and Safety of S-1 Plus Oxaliplatin in First-line Treatment of Ederly Patients With Advanced Gastric Cancer

Inclusion Criteria:

* Histologically confirmed unresectable or recurrent gastric or gastroesophageal junction adenocarcinoma;
* Aged≥60
* ability of oral administration;
* CT or MRI can be used to assess measurable or non-measurable lesions according to the criteria of Response Evaluation Criteria In Solid Tumours (RECIST 1.1);
* Untreated
* more than 12 months after the last adjuvant/neoadjuvant chemotherapy;
* ECOG=0-2;
* Available organ function: ALT≤2.5xULN;AST≤2.5xULN;If patients have hepaticmetastasis,ALT≤2.5xULN,AST≤2.5xULN;ALP≤2xULN;TBIL≤1.0xULN;NEUT≥1.5×109/L;PLT≥100×109/L;Hb≥90g/L;Creatinine≤1.0xULN;Creatinine Clearance≥60ml/min
* Informed consent;
* Expected survival more than 3 months;More than 3 weeks after major surgery.

Exclusion Criteria:

* Neoadjuvant and/or adjuvant have been treated with more than two plans;
* In the past two years, the total dose of oxaliplatin≥800mg/m2;
* Other cancers in the past 5 years,except for cervical carcinoma in situ or non-melanoma skin cancer;
* Symptomatic brain metastases or soft meningeal metastasis;
* Myocardial infarction (in the last 6 months), severe instability angina, congestive heart failure;
* Serious complications (including intestinal paralysis, gastrointestinal obstruction, interstitial pneumonia, pulmonary fibrosis, uncontrolled diabetes, renal insufficiency and cirrhosis); Chronic nausea, vomiting or diarrhea (more than 4 times per day, or watery);Gastrointestinal bleeding requires regular blood transfusion;HIV or AIDS; Mental illness; Neuropathy grade≥2;Infectious diseases or inflammation, temperature≥38℃;
* Known allergy to drugs in the study;
* Pregnant or lactating women;
* Both male and female subjects of potential fertility have to agree effective birth control during the entire study;
* Experimental drugs used no more than 4 weeks;
* Other conditions the researchers considered ineligible for the study.