DISEASE CHARACTERISTICS:

• Histologically confirmed carcinoma of the nasopharynx

  • WHO type I, II, or III
  • Recurrent locoregional or metastatic disease

  • The following primary tumor sites or types are excluded:

    • Nasal cavity
    • Paranasal sinus
    • Sinonasal neuroendocrine carcinoma
    • Primary malignancy of the salivary gland

• Received at least 1, but no more than 2, prior chemotherapy regimens for recurrent locoregional or metastatic disease

  • Patients who are intolerant of OR have a condition that precludes platinum-based chemotherapy are eligible
• Available tumor tissue

• Measurable disease

  • At least 1 lesion that has not been irradiated within the past 6 months
  • More than 10 mm by spiral CT scan (20 mm by conventional techniques)
  • Pleural effusion or bone metastases are not considered measurable disease
• No CNS metastases unless stable for > 3 months

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-1

Life expectancy

• More than 3 months

Hematopoietic

• Neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT ≤ 2.5 times ULN (5 times ULN if due to liver metastases)
• Alkaline phosphatase ≤ 2.5 times ULN (5 times ULN if due to liver metastases; 10 times ULN if due to bone metastases)

Renal

• Creatinine clearance ≥ 30 mL/min OR
• Creatinine ≤ 1.5 times ULN

Cardiovascular

• No congestive heart failure
• No symptomatic coronary artery disease
• No cardiac arrhythmias not well controlled by medication
• No myocardial infarction within the past year
• No other clinically significant cardiac disease

Neurologic

• No history of uncontrolled seizures
• No clinically significant CNS disorder or psychiatric disability that would preclude giving informed consent or complying with study treatment

Immunologic

• No prior unanticipated severe reaction to fluoropyrimidines
• No extreme sensitivity to fluorouracil
• No serious, uncontrolled infection

Other

• No other malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix
• No malabsorption syndrome of the upper gastrointestinal tract
• No other serious uncontrolled medical condition that would preclude study participation
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics
• More than 6 months since prior fluoropyrimidines, including fluorouracil
• More than 4 weeks since prior chemotherapy and recovered

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• More than 4 weeks since prior radiotherapy

Surgery

• More than 4 weeks since prior major surgery and recovered

Other

• More than 4 weeks since prior investigational drugs