Isotretinoin, Interferon Alfa, and Vitamin E in Treating Patients With Stage III or Stage IV Head and Neck Cancer

RATIONALE: Drugs used in chemotherapy such as isotretinoin use different ways to stop tumor cells from dividing so they stop growing or die. Interferon alfa may interfere with the growth of tumor cells. Vitamin E may be able to decrease side effects caused by isotretinoin. It is not yet known whether combining isotretinoin and interferon alfa with vitamin E is more effective than observation in preventing recurrence of head and neck cancer after surgery and/or radiation therapy. PURPOSE: Randomized phase III trial to compare the effectiveness of isotretinoin and interferon alfa combined with vitamin E with that of observation in treating patients who have undergone surgery and/or radiation therapy for stage III or stage IV head and neck cancer.