Radiation Therapy Cisplatin With or Without Fluorouracil Patients With Stage III or Stage IV Head and Neck Cancer

RATIONALE: Radiation therapy uses high energy x-rays to kill tumor cells. Drugs used in chemotherapy, such as cisplatin and fluorouracil, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving radiation therapy together with cisplatin and fluorouracil may kill more tumor cells. It is not yet known whether radiation therapy and cisplatin are more effective with or without fluorouracil in treating patients with head and neck cancer. PURPOSE: This randomized phase III trial is studying radiation therapy and cisplatin to compare how well they work with or without fluorouracil in treating patients with stage III or stage IV head and neck cancer.