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 keratoconjunctivitis sicca * No severe exposure keratopathy * No abnormal slit-lamp examination using a vital dye (e.g., fluorescein or Bengal-Rose) * No abnormal corneal sensitivity test (Schirmer test or similar tear production test) * No disorder that might increase the risk for epithelium-related complication (e.g., bullous keratopathy, aniridia, severe chemical burns, or neutrophilic keratitis) * No congenital abnormality (e.g., Fuch's dystrophy) * No ocular inflammation or infection Gastrointestinal * Able to take oral medication * No gastrointestinal (GI) tract disease requiring IV alimentation * No uncontrolled inflammatory GI disease (e.g., Crohn's disease or ulcerative colitis) * No active peptic ulcer disease Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No serious active infection * No other serious underlying medical condition that would preclude study participation * No prior allergic reaction to compounds of similar chemical or biological composition to erlotinib * No other malignancy with the past 5 years except adequately treated non-melanoma skin cancer (unless in the same area treated with radical radiotherapy) or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * See Disease Characteristics * Recovered from prior chemotherapy Endocrine therapy * Not specified Radiotherapy * See Disease Characteristics * Recovered from prior radiotherapy Surgery * See Disease Characteristics * No prior surgical procedure affecting absorption * No concurrent ophthalmic surgery Other * More than 4 weeks since other prior investigational drugs * No other concurrent investigational agents * No other concurrent anticancer therapy * Concurrent oral anticoagulants (e.g., warfarin) allowed provided there is increased vigilance with respect to INR * Concurrent nasogastric or gastrostomy tube feeding for dysphagia allowed provided there is no evidence of significant residual mucositis (i.e., \> grade 1)