Nivolumab, Ipilimumab and Chemoradiation in Treating Patients With Resectable Gastric Cancer

This pilot phase I/II trial studies the side effects and how well nivolumab and ipilimumab in combination with chemotherapy and radiation therapy work in treating patients with gastric cancer that can be removed by surgery. Immunotherapy with monoclonal antibodies, such as nivolumab and ipilimumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Drugs used in chemotherapy, such as oxaliplatin and fluorouracil, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Intensity-modulated radiation therapy uses thin beams of radiation of different strengths aimed at the tumor from many angles. This type of radiation therapy may reduce the damage to healthy tissue near the tumor. Giving nivolumab, ipilimumab, chemotherapy and radiation therapy may work better in treating patients with gastric cancer.