DISEASE CHARACTERISTICS:

• Histologically proven squamous cell carcinoma of the head and neck

  • Metastatic disease at diagnosis OR
  • Persistent, metastatic, or recurrent disease after prior definitive surgery and/or radiotherapy
• No undifferentiated and nonkeratinizing carcinomas, including lymphoepitheliomas of all locations
• No nasopharynx tumors

• Bidimensionally measurable disease

  • Patients whose only measurable disease is within a prior radiotherapy port must have clearly progressive disease
• No metastatic or leptomeningeal CNS disease

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Platelet count greater than 100,000/mm^3
• Absolute granulocyte count greater than 1,500/mm^3

Hepatic:

• See Other (Prior/Concurrent Therapy)
• SGOT and SGPT less than 2.5 times normal
• Bilirubin less than 1.5 times normal
• No history of hypercoagulopathies (e.g., protein C deficiency, protein S deficiency, or lupus anticoagulant)

Renal:

• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 60 mL/min
• Calcium no greater than normal
• No hypercalcemia refractory to bisphosphonates

Cardiovascular:

• No unstable or newly diagnosed angina pectoris
• No myocardial infarction within the past 6 months
• No class II-IV congestive heart failure
• No history of symptomatic carotid disease
• No concurrent asymptomatic carotid artery occlusion (70% or greater) in one or both arteries by Doppler ultrasound
• No symptomatic atherosclerosis
• No thrombotic events within the past 6 months

Pulmonary:

• No aspirin-induced asthma

Other:

• No inability to take aspirin or clopidogrel bisulfate due to contraindications, allergies, or pre-existing medical conditions (e.g., active peptic ulcer disease or history of undiagnosed non-occult, non-hemorrhoidal gastrointestinal or other bleeding sources within the past 6 months)
• No other prior malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer that is currently in complete remission
• HIV negative
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent biologic therapy

Chemotherapy:

• At least 4 weeks since prior chemotherapy and recovered
• No prior flavopiridol
• No more than 3 prior systemic chemotherapy regimens for recurrent or metastatic disease
• No other concurrent chemotherapy

Endocrine therapy:

• No concurrent hormonal therapy except oral contraceptives

Radiotherapy:

• See Disease Characteristics
• At least 4 weeks since prior radiotherapy and recovered
• No concurrent radiotherapy

Surgery:

• See Disease Characteristics
• At least 4 weeks since prior surgery and recovered
• No prior carotid endarterectomy or other revascularization surgery

Other:

• No other concurrent antineoplastic therapies
• No active anticoagulation with INR 1.5 or greater
• No low-molecular weight heparin or equivalent
• Concurrent bisphosphonates for calcium maintenance allowed