Adjuvant Erlotinib After Completing Chemoradiotherapy in Locally Advanced Squamous Cell Carcinoma of the Head and Neck

DISEASE CHARACTERISTICS: * Histologically confirmed squamous cell carcinoma of the head and neck * Stage III, IVA, or IVB * Must have completed cisplatin- or carboplatin-based chemoradiotherapy within the past 4-12 weeks * Prior radiotherapy must have been given with a radical intent with receipt of at least 90% of planned dose * No evidence of disease or presence of inoperable minimal residual disease, defined by 1 of the following: * Complete response at primary tumor site and nodes (with or without nodal surgery after chemoradiotherapy) * Negative lymph node status (by physical or radiological exam) AND persistent tumefaction less than 25% of original tumor size or residual mass due to scarring * Tumor tissue samples available for EGFRvIII mutation analysis * No known brain metastasis PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-1 Life expectancy * Not specified Hematopoietic * Absolute granulocyte count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 Hepatic * ALT/AST \< 2 times upper limit of normal (ULN) * Bilirubin \< ULN (unless due to Gilbert's syndrome) Renal * Creatinine \< 1.5 times ULN Cardiovascular * No myocardial infarction within the past year * No cardiac ventricular arrhythmias requiring medication * No history of cardiac disease * No uncontrolled high blood pressure * No unstable angina * No congestive heart failure Ophthalmic * No history of severe dry eye syndrome, Sjögren's syndrome, or keratoconjunc…