DISEASE CHARACTERISTICS:

• Histologically confirmed squamous cell carcinoma of the oral cavity (OC) or oropharynx (OP)

  • OC sites include: oral tongue, buccal mucosa, floor of mouth, retromolar trigone, alveolar ridge, hard palate, and mucosal lip
  • OP sites include: base of tongue, tonsil, soft palate, and oropharyngeal wall
  • Stage II (T2, N0) or III (T1-2, N1) (eligible for regimen A only)
  • Stage III (T3, N0-1) or IV (T1-4, N2-3, M0 or T4, N0-1, M0) (eligible for regimen B only)
• Documentation of evaluable tumor within the past 4 weeks
• Operable or inoperable tumors allowed
• No known brain involvement
• No prior head and neck malignancies

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2 OR
• Karnofsky 60-100%

Life expectancy

• At least 6 months

Hematopoietic

• WBC at least 3,000/mm^3
• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic

• Bilirubin normal (unless due to hemolysis or Gilbert's syndrome)
• AST/ALT no greater than 2.5 times upper limit of normal
• aPTT/INR normal (correctable with vitamin K)

Renal

• Creatinine normal OR
• Creatinine clearance at least 60 mL/min

Cardiovascular

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No untreated or new cardiac arrhythmia

Ophthalmic

• No abnormalities of the cornea (e.g., dry eye syndrome or Sjögren's syndrome)
• No congenital abnormalities (e.g., Fuch's dystrophy)
• No abnormal slit-lamp examination using a vital dye (e.g., fluorescein or Bengal-Rose)
• No abnormal corneal sensitivity test (e.g., Schirmer test or similar tear production test)

Gastrointestinal

• G-tube dependency allowed
• No gastrointestinal tract disease resulting in an inability to take oral medication or a requirement for IV alimentation
• No active peptic ulcer disease
• No known malabsorption syndrome

Other

• No other concurrent uncontrolled illness that would preclude study participation
• No ongoing or active infection
• No uncontrolled diabetes mellitus
• No psychiatric illness or social situation that would preclude study participation
• No prior allergic reactions attributed to compounds of similar chemical or biological composition to erlotinib or other study agents
• No significant traumatic injury within the past 28 days
• No other malignancy within the past 3 years except completely resected basal cell skin cancer or carcinoma in situ of the cervix
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior immunotherapy for this malignancy

Chemotherapy

• No prior chemotherapy for this malignancy

Endocrine therapy

• Not specified

Radiotherapy

• No prior radiotherapy for this malignancy

Surgery

• No prior surgical procedures affecting absorption
• At least 28 days since prior major surgery

Other

• No prior epidermal growth factor receptor-targeting therapies for this malignancy
• No prior investigational agents for this malignancy
• No other prior therapy for this malignancy
• No concurrent commercial or other investigational anticancer agents or therapies
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No concurrent warfarin