Combination Chemotherapy in Treating Patients With Advanced Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed non-small cell lung cancer (NSCLC) * Unresectable stage IIIB (e.g., pleural effusion) not suitable for combined modality therapy OR * Stage IV * Prior brain metastases are allowed provided the following are true: * Patient completed radiotherapy and/or surgery at least 3 weeks prior to study * Objective evidence of resolution or significant improvement of brain lesions exists on follow-up CT scan or MRI * Patient is neurologically improved or stable PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * ECOG 0-1 Life expectancy: * Not specified Hematopoietic: * Absolute granulocyte count at least 1,500/mm\^3 * WBC at least 3,000/mm\^3 * Hemoglobin at least 9 g/L * Platelet count at least 100,000/mm\^3 Hepatic: * Bilirubin no greater than 1.25 mg/dL * SGOT no greater than 1.5 times upper limit of normal Renal: * Creatinine no greater than 2.0 mg/dL OR * Creatinine clearance at least 50 mL/min Cardiovascular: * No prior uncontrolled cardiovascular disease * No hospitalization for acute myocardial infarction, arrhythmia, or congestive heart failure within the past 3 months Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective nonhormonal contraception * No serious active infection * No dementia or active psychoses * No other prior malignancy except nonmetastatic nonmelanoma skin cancer, carcinoma in situ of the cervix, or cancer curatively treated with surgery or small-field radiotherapy within the past 5 years PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * No prior chemotherapy Endocrine therapy: * Not specified Radiotherapy: * See Disease Characteristics * At least 3 weeks since prior radiotherapy Surgery: * See Disease Characteristics Other: * At least 1 month since prior investigational agents * More than 7 days since prior aspirin, sulindac, cyclo-oxygenase-2 (COX-2) inhibitors, or nonsteroidal anti-inflammatory drugs (except ibuprofen or naproxen) * No concurrent sulindac or COX-2 inhibitors