Proteomic Profiling in Predicting Response in Patients Receiving Erlotinib for Stage IIIB, Stage IV, or Recurrent Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed non-small cell lung cancer (NSCLC), meeting 1 of the following criteria: * Stage IIIB (with pleural effusion) or stage IV disease * Recurrent disease after prior surgery * Measurable or evaluable disease is desirable but not required * No untreated symptomatic brain metastases * Patients who are neurologically unstable despite radiotherapy for the brain metastases are not eligible * No requirement for steroids to control neurological symptoms PATIENT CHARACTERISTICS: * ECOG performance status 0-2 * ANC ≥ 1,500/mm³ * Hemoglobin ≥ 9 g/dL * Platelet count ≥ 100,000/mm³ * Creatinine ≤ 2.0 mg/dL * Total bilirubin ≤ 1.5 mg/dL * Normal hemostasis by history * PT/PTT within 0.5 seconds of normal range * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Willing to undergo biopsy procedures * No known severe hypersensitivity to erlotinib hydrochloride or any of the excipients of this product * No other concurrent malignancies or malignancies diagnosed within the past 5 years, except basal cell carcinoma or cervical cancer in situ * No significant cardiac disease, including any of the following: * NYHA class III or IV heart disease * Uncontrolled dysrhythmia * Myocardial infarction within the past 6 months * No evidence of clinically active interstitial lung disease * Chronic stable radiographic changes that are asymptomatic allowed * No evidence of any other severe or uncontrolled systemic disease (e.g., unstable or uncompensated respiratory, cardiac, hepatic, or renal disease) * No evidence of any other significant clinical disorder or laboratory finding that makes it undesirable for the patient to participate in the trial * No uncontrolled hypertension * Blood pressure must be ≤ 150/90 mmHg on a stable antihypertensive regimen PRIOR CONCURRENT THERAPY: * See Disease Characteristics * At least 6 months since prior adjuvant chemotherapy * No unresolved chronic toxicity \> CTC grade 2 from prior anticancer therapy (except alopecia) * More than 30 days since prior non-approved or investigational drugs * No prior chemotherapy for advanced NSCLC * No concurrent phenytoin, carbamazepine, rifampin, barbiturates, or St. John's wort * No concurrent administration of other drugs known to inhibit EGFR * No other concurrent anti-neoplastic or anti-tumor agents, including chemotherapy, radiotherapy, immunotherapy, or hormonal anticancer therapy * No other concurrent investigational agents * Concurrent cardioprotective doses of aspirin, as recommended by the physician, for cardiovascular disease allowed