Inclusion Criteria

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