Study of XELOX With Cetuximab in Advanced Gastric Cancer

Inclusion Criteria:

* Having given signed written informed consent
* Patients must have histologically or cytologically documented stomach adenocarcinoma including adenocarcinoma of the esophagogastric junction.
* Patients must have unresectable metastatic disease or recurrent disease after curative surgical resection with uni-dimensionally measurable disease according to RECIST (at least longest diameter 1 cm on computed tomography scan, or at least 2 cm on chest x-ray or physical examination
* Age 18 to 70 years old
* Estimated life expectancy of more than 3 months
* ECOG performance status \< 2 (See Appendix E)
* Adequate bone marrow function (WBC\>3,000/µL, ANC\>1,500/µL, and platelets\>100,000/µL, Hb\>8g/dl)
* Adequate kidney function (creatinine\<1.5 mg/dL)
* Adequate liver function \[bilirubin\< 2.0 mg/dL, transaminases levels\<3 times the Upper Normal Value (5 times for patients with liver metastasis)\]
* Prothrombin time not less than 50% of Lower Normal Value
* No prior chemotherapy
* No prior radiation therapy
* Patients must not have psychological, familial, sociological or geographical conditions which do not permit medical follow-up and compliance with this study.
* Women of childbearing potential must have a negative serum HCG pregnancy test on admission. Men and women of reproductive potential must have agreed to use an effective method of contraception while on treatment and for 6 months after study treatment.

Exclusion Criteria:

* Past or concurrent history of neoplasm other than gastric adenocarcinoma within the last five years, except for curatively treated non-melanoma skin cancer or in situ carcinoma of the cervix uteri.
* Central nervous system (CNS) metastases.
* Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to study treatment start
* Gastric outlet obstruction, intestinal obstruction and obvious peritoneal seeding.
* Evidence of serious gastrointestinal bleeding.
* The patient has bony lesions as the sole evaluable disease.
* Pregnant or lactating women, women of childbearing potential not employing adequate contraception.
* Patients with sensory neuropathy (grade\> 1 according to NCI CTCAE v. 3.0).
* Hypersensitivity to any of the study drugs or ingredients.
* Other serious illness or medical conditions that would not allow study participation in the best interest of the patient as decided by the investigator.
* Unstable cardiac disease despite treatment, myocardial infarction within 6 months prior to study entry.
* History of significant neurologic or psychiatric disorders including dementia or seizures.
* Active uncontrolled infection.
* Pre-existing clinically significant diarrhea.
* Unstable diabetes mellitus.
* Severe hypercalcemia of \> 12 mg/dL and uncontrolled with bisphosphonates.
* Active disseminated intravascular coagulation.
* Concurrent treatment with corticosteroids (or equivalent) except as use for the prophylactic medication regimen, treatment of acute hypersensitivity reactions or nausea, or unless chronic treatment (initiated \> 6 months prior to study entry) at low dose (\<20 mg methyl prednisolone or equivalent).
* Concomitant or administration of any other experimental drug under investigation within 4 weeks before the study.
* Concomitant or previous hormonal therapy, or immunotherapy.