Gefitinib as First-Line Therapy Followed by Gemcitabine and Cisplatin in Treating Patients With Stage III or Stage IV Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: Histologically* or cytologically* confirmed non-small cell lung cancer (NSCLC), including any of the following cellular subtypes: Squamous cell carcinoma Adenocarcinoma Large cell carcinoma Poorly differentiated NSCLC NOTE: *New biopsies or cytologic specimens required for primary resection specimens older than 2 years De novo or recurrent disease, meeting 1 of the following stage criteria: Stage IIIB disease Malignant pleural effusion OR supraclavicular node involvement (N3) Not suitable for curative multimodal treatment or surgery Stage IV disease Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan or MRI Measurable lesion must be outside previously irradiated areas Immediate chemotherapy is not clinically mandatory No small cell lung cancer (SCLC) or SCLC combined with NSCLC No symptomatic and/or untreated brain metastases PATIENT CHARACTERISTICS: Age 18 and over Performance status WHO 0-1 Life expectancy Not specified Hematopoietic Absolute neutrophil count ≥ 1,500/mm^3 Platelet count ≥ 100,000/mm^3 Hemoglobin ≥ 10.0 g/dL Hepatic Bilirubin normal AST or ALT ≤ 2.5 times upper limit of normal (ULN) Alkaline phosphatase ≤ 2.5 times ULN (5 times ULN in the presence of bone metastases) No unstable or uncompensated hepatic disease Renal Creatinine clearance > 60 mL/min No unstable or uncompensated renal disease Cardiovascular No unstable or uncompensated cardiac disease No myocardial infarction within the past 3 months Pulmonary No clinically active interstitial lung disease Asymptomatic patients with chronic stable radiographic changes allowed No unstable or uncompensated respiratory disease Other Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 12 months after completion of study treatment Able to swallow and retain oral medication No active infection No uncontrolled diabetes mellitus No history of allergic reactions or hypersensitivity attributed to compounds of similar chemical or biological composition to study drugs No other severe or uncontrolled systemic disease No other serious underlying medical condition that would preclude study participation No psychiatric disability that would preclude study compliance or giving informed consent No other malignancy within the past 5 years except adequately treated nonmelanoma skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy Prior intrapleural or intrapericardial local chemotherapy allowed No prior chemotherapy for advanced disease More than 6 months since prior neoadjuvant or adjuvant systemic chemotherapy for NSCLC Endocrine therapy Not specified Radiotherapy See Disease Characteristics Concurrent palliative radiotherapy allowed (except to brain metastases) Surgery Not specified Other No prior epidermal growth factor receptor-targeted therapy for NSCLC No concurrent use of any of the following CYP3A4 inducers: Phenytoin Carbamazepine Rifampin Barbiturates Hypericum perforatum (St. John's wort) More than 30 days since prior participation in another clinical trial No other concurrent investigational agent