In China, S-1 is an novel oral fluoropyrimidine with demonstrated high efficacy on gastrointestinal cancer. The new regimen with oxaliplatin and leucovorin is expected to achieve more encouraging efficacy on gastric cancer. This study is aimed to evaluate the feasibility of the SOL regimen on efficacy and tolerability on Chinese patients with advanced gastric cancer.

Inclusion Criteria:

• Age over 18 years old
• Histologically or cytologically documented gastric adenocarcinoma
• Performance status (ECOG scale): 0-2
• Life expectancy ≥ 3 months
• No previous treatment(including: radiotherapy,chemotherapy and immunotherapy)
• Prior systemic therapy (for instance, cytotoxic chemotherapy or active/passive immunotherapy) for adjuvant or neoadjuvant treatment for non-metastatic (M0) disease has been completed within 6 months prior to initiation of study treatment.
• WIth Measurable Target lesion
• Patients should sign a written informed consent before study entry

Exclusion Criteria:

• History of hypersensitivity to fluoropyrimidines, S-1, oxaliplatin or the ingredients product
• Inadequate hematopoietic function: WBC≦5,000/mm3; ANC≦2,000/mm3; Platelet≦100,000/mm3
• Inadequate organ function which is defined as below:

Total bilirubin >2 pper limit of normal range (ULN); ALT / AST > 2.5 upper limit of normal range (ULN) (>5.0 x ULN if hepatic metastasis); serum creatinine > 2 upper limit of normal range (ULN);

• Symptomatic peripheral neuropathy ≥ NCI CTC AE grade 1;
• Receiving a concomitant treatment with other fluoropyrimidines or fluorocytosine;
• Pregnancy or lactation women, or women with suspected pregnancy or men unless using a reliable and appropriate contraceptive method;
• Mental status is not fit for chemotherapy therapy presence of serious concomitant illness which might be aggravated by study medication;
• History of ventricular arrhythmia or congestive heart failure;
• Active cardiac disease e.g. decompensate myocardial infarction within the 6-month period preceding entry into the study;
• Significant co-morbid medical conditions, including, but not limited to, Chronic obstructive pulmonary disease, interstitial pneumonia ,pulmonary heart failure, renal failure, hepatic failure, haemorrhagic peptic ulcer, mechanical, paralytic or poor control diabetes