S0425 Oxaliplatin, Capecitabine, and RT in Treating Patients W/Stomach Cancer That Can Be Removed By Surgery

RATIONALE: Drugs used in chemotherapy, such as oxaliplatin and capecitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving chemotherapy together with radiation therapy before surgery may make the tumor smaller and reduce the amount of normal tissue that needs to be removed. PURPOSE: This phase II trial is studying how well giving oxaliplatin and capecitabine together with radiation therapy works in treating patients with stomach cancer that can be removed by surgery.