S-1, Cisplatin, and Radiation Therapy in Treating Patients With Stage IIA, Stage III, or Stage IVA Esophageal Cancer That Can Be Removed by Surgery

RATIONALE: Drugs used in chemotherapy, such as S-1 and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving radiation therapy together with more than one drug (combination chemotherapy) may kill more tumor cells. PURPOSE: This phase II trial is studying how well giving S-1 and cisplatin together with radiation therapy works in treating patients with stage IIA, stage III, or stage IVA esophageal cancer that can be removed by surgery.