RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage tumor cells. Combining more than one chemotherapy drug with radiation therapy may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of combination chemotherapy plus radiation therapy in treating patients who have head and neck cancer.

OBJECTIVES: I. Determine the toxicity of fluorouracil and cisplatin with concurrent radiotherapy in patients with stage I-IVB squamous cell cancer of the head and neck at high risk of recurrence following curative resection. II. Determine the efficacy of this regimen in these patients. III. Determine the survival of these patients treated with this regimen.

OUTLINE: This is a multicenter study. Patients receive fluorouracil IV continuously on days 1-5 and 43-47 and cisplatin IV over 1 hour on days 2, 23, and 44. Concurrent radiotherapy is administered 5 days a week for 6.5 weeks. Patients are followed every 3 months for 2 years, then every 6 months for 3 years.

PROJECTED ACCRUAL: A total of 44-68 patients will be accrued for this study within 18 months.

DISEASE CHARACTERISTICS: Histologically proven stage I-IVB squamous cell cancer of the oral cavity, oropharynx, hypopharynx, or larynx Positive lymph nodes allowed, either bilateral or contralateral Curatively resected within past 6 weeks No distant metastases

PATIENT CHARACTERISTICS: Age: Over 18 to 70 Performance status: Karnofsky 70-100% Life expectancy: Not specified Hematopoietic: WBC at least 2,000/mm3 Platelet count at least 150,000/mm3 Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) SGOT and SGPT less than 2 times ULN Alkaline phosphatase less than 2 times ULN Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance greater than 70 mL/min Cardiovascular: No contraindication to fluorouracil IV No coronary artery disease greater than grade 2 No unstable heart disease Other: No other malignancy except basal cell skin cancer or carcinoma in situ of the cervix Not pregnant Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy Surgery: See Disease Characteristics Other: No other concurrent adjuvant therapy No concurrent preventive treatment (e.g., retinoids) No other concurrent experimental treatment