Short-Course Chemoradiotherapy Followed by Chemotherapy for the Treatment of Resectable Gastric Adenocarcinoma

PRIMARY OBJECTIVE: I. To assess the safety and tolerability of preoperative short-course chemoradiotherapy (CXRT) in patients with potentially resectable gastric adenocarcinoma. SECONDARY OBJECTIVES: I. To assess the rate of pathologic complete response (pathCR) in patients treated with preoperative short-course CXRT. II. To assess the rate of perioperative complications after gastrectomy in patients treated with preoperative short-course CXRT. III. To assess overall survival from the date of diagnosis in subjects treated with short course CXRT. OUTLINE: Patients receive CXRT consisting of radiation therapy 5 days a week (Monday through Friday) for 2 weeks (10 treatments) and standard of care chemotherapy consisting of capecitabine orally (PO) twice daily (BID) or fluorouracil intravenously (IV) continuous Monday to Friday of each radiation week. About 2 weeks later, patients receive standard of care chemotherapy for up to 2 months in the absence of disease progression or unacceptable toxicity. Patients then undergo standard of care surgery 3-8 weeks post-chemotherapy completion. After the completion of study treatment, patients are followed up every 6 months for 5 years.