The purpose of this study is to evaluate the efficacy and tolerability of the combination of epirubicin, oxaliplatin and 5-day continuous infusional 5-fluorouracil (EOF5 regimen) in patients with unresectable advanced or metastatic gastric cancer (A/MGC). Since Mar 2011, two addition second endpoints was added to the trial, one was to compare the consistence of two types of PET Scan evaluation with routine CT Scan evaluation, the other was to search for predictor factors of clinical results ( ORR,PFS and OS) with Pharmacogenomics methods. This modification was approved by the Ethic Committee of Fudan University Cancer Hospital, and the approval number was IRB50-15-1101A.

ECF regimen is considered as a reference regimen for gastric cancer in Europe. Now, no regimen has been proved to be more effective while less toxicity than ECF regimen. Oxaliplatin has demonstrated synergy with 5-FU in vitro, in vivo, and in the clinical setting in advanced colorectal cancer. It presents a better toxicity profile than cisplatin. Recently some studies used combination regimens of oxaliplatin, folinic acid, and continuous infusion 5-FU for about 44 hours (e.g FOLFOX4 ) to treat A/MGC, and yielded good response rates and median overall survival times while resulting in lower rates of grade 3-4 adverse events. Therefore, it is logical to modify ECF regimen with oxaliplatin replacing cisplatin and a short-term FU infusion replacing 21-day FU infusion. Our objective is to evaluate whether the EOF5 regimen is less toxicity while is comparable effective as ECF regimen.

Inclusion Criteria:

• Histologically confirmed advanced or metastatic adenocarcinoma of the stomach
• ECOG performance scale ≤2
• At least one measurable lesion (larger than 10 mm in diameter by spiral CT scan)
• Adequate hepatic, renal, heart, and hematologic functions (platelets >80×109/L, neutrophil>2.0×109/L, serum creatinine ≤1.5mg/dl, total bilirubin within upper limit of normal(ULN), and serum transaminase≤2.5×the ULN)

Exclusion Criteria:

• Pregnant or lactating women
• Concurrent cancer
• History of other malignancies except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix
• Neuropathy, brain, or leptomeningeal involvement
• Clinically relevant coronary artery disease or a history of a myocardial infarction within the last 12 months or high risk/uncontrolled arrhythmia
• Uncontrolled significant comorbid conditions and previous radiotherapy