To investigate the feasibility, safety and tolerability of Preoperative Chemoradiation in Patients With Localized Gastric Cancer. Primary endpoint: R0 resection rate. Secondary endpoint: resection rate, pathological complete regression (pCR), effectiveness and safety of regime, disease free survival(DFS) and overall survival(OS).

The prognosis of gastric cancer is poor partially due to low R0 resection rate. Neoadjuvant chemoradiotherapy was reported to be effective in this setting by several phase II studies. The investigators aim to evaluate the efficacy and toxicity of neoadjuvant chemoradiotherapy in a prospective phase II study.

Inclusion Criteria:

1.18 ≤ age ≤ 70, Male or Female; 2.Minimum life expectancy of 6 months; 3.Patients with localized, histologically confirmed gastric or gastroesophageal adenocarcinoma; 4.Patients must have a performance status of < 2 Eastern Cooperative Oncology Group (ECOG); 5.No prior major surgery of the stomach or radiation therapy to the stomach or immunotherapy or chemotherapy; 6.CT or MRI, endorectal ultrasonography (EUS), laparoscopic exploration are required to stage; 7.Without other benign diseases such as lung, kidney, liver infections; 8.Without participating other clinical trials; 9.Patient must sign an informed consent prior to study entry; 10.Patients must have adequate bone marrow function (defined as peripheral absolute granulocyte count of >1,500/µL, and platelet count of > 100,000/µL), adequate liver function (bilirubin <= 1.5 mg/dl), and adequate renal function (creatinine <= 1.5 mg/dl). 11)Patients without cardiac disease , severe uncontrolled diabetes, hypertension, cerebrovascular disease, or infection.

Exclusion Criteria:

1. Pregnant women are excluded from study entry due to the potential teratogenic effects of the study treatment;
2. Female patients who planed to have a baby;
3. Prior radiation therapy to the stomach, liver or kidney;
4. Dysfunction of important organs such as liver, kidney or heart; 5.Abnormalities of mental status;

6.Active coronary artery disease; 7.Cardiac arrhythmia, and need to receive medication therapy; 8.Severe uncontrolled hypertension; 9.Active clinical serious infection; 10.The known human immunodeficiency virus (HIV) infection history; 11.The known central nervous system diseases, including brain metastatic tumors; 12.Patients have had clinical clear gastrointestinal bleeding in 6 months; 13.Drug abuse; 14.Swallowing difficulties for drugs; 15.Poor compliance; 16.Presence of concurrent or previous malignancies (except for cervical carcinoma in situ or basal cell carcinoma of the skin); 17.Presence of peritoneal metastasis, distant organs or lymph nodes metastasis; 18.Presence history of major surgery in the past three months; 19.Poor tolerability; 20.Prior history of medication; 21.allergy for chemotherapeutic drugs.