S0225 Capecitabine in Treating Patients Who Have Undergone Surgery for Locally Recurrent or Persistent Head and Neck Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed squamous cell carcinoma of the head and neck * Locoregionally recurrent or persistent disease * No thyroid gland, salivary gland, or nasopharynx disease sites * Must have undergone definitive or post-operative radiotherapy at the time of initial curative treatment * Must have undergone salvage surgical resection within the past 56 days * All current disease must be completely resected, including resection of recurrent primary disease and/or neck dissection, if regional nodal disease is present * Surgical margins must be free of disease on final pathological evaluation of specimens * No definitive or adjuvant radiotherapy or reirradiation for recurrent or persistent disease allowed at the time of salvage treatment * No evidence of distant disease by clinical examination and CT scan of the chest and upper abdomen (including the liver) within the past 90 days PATIENT CHARACTERISTICS: Age * 18 and over Performance status * Zubrod 0-1 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 Hepatic * Not specified Renal * Creatinine clearance ≥ 30 mL/min Other * Not pregnant or nursing * Fertile patients must use effective contraception * Able to take oral tablets OR able to take crushed tablets through a gastrostomy tube * No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent biologic therapy * No concurrent filgrastim (G-CSF) Chemotherapy * Prior systemic chemotherapy as definitive therapy for head and neck cancer allowed (prior treatment with fluorouracil allowed, but must be catalogued) * More than 5 years since prior systemic chemotherapy for any other cancer diagnosis * No other concurrent chemotherapy Endocrine therapy * No concurrent anticancer hormonal therapy * Concurrent hormonal therapy for non-cancer diagnosis allowed Radiotherapy * See Disease Characteristics * No concurrent radiotherapy Surgery * See Disease Characteristics * Recovered from prior surgery