Postoperative Chemoradiation or Chemotherapy After Preoperative Chemotherapy for Gastric Cancers

This is an open-label, stratified, two arm design. All patients receive same initial standard preoperative chemotherapy and surgical resection. Patients will then be assigned to either standard postoperative chemotherapy if node negative at surgery or standard postoperative chemoradiation if node positive at surgery. The primary objective of this study is to determine the feasibility of patients enrolling and receiving either postoperative chemoradiation or chemotherapy alone, based upon nodal status at surgery, following preoperative chemotherapy. The secondary Objectives is to evaluate the rate of cancer recurrence in patients assigned to treatment based upon node status. To explore the potential correlation between changes in expression of a pre-specified panel of genes identified as relevant to gastrointestinal cancers in response to preoperative chemotherapy, using presence of nodal involvement at time of surgery as an indicator of response.