Carboplatin and Gemcitabine Combined With Celecoxib and/or Zileuton in Treating Patients With Advanced Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed non-small cell lung cancer (NSCLC) of 1 of the following cellular types: * Adenocarcinoma * Large cell * Squamous cell * Mixed * Meets 1 of the following staging criteria: * Stage IIIB disease with malignant pleural effusion, supraclavicular node involvement, or contralateral hilar nodes * Stage IIIB patients eligible for Cancer and Leukemia Group B protocols of combined chemotherapy and chest irradiation are not allowed * Stage IV disease * Measurable or nonmeasurable disease * Unidimensionally measurable lesions at least 20 mm by conventional techniques OR at least 10 mm by spiral CT scan * The following are considered nonmeasurable disease: * Bone lesions * Ascites * Pleural/pericardial effusion * Lymphangitis cutis/pulmonis * Abdominal masses that are not confirmed and followed by imaging techniques * Cystic lesions * Small lesions * No leptomeningeal disease * Symptomatic CNS metastases must be treated (e.g., surgery, radiotherapy, or gamma knife), neurologically stable, and off steroids PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * Not specified Hematopoietic * Granulocyte count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Bilirubin no greater than 1.5 mg/dL * AST no greater than 2.0 times upper limit of normal Renal * Creatinine no greater than 1.5 mg/dL Cardiovascular * None of the following within the past 6 months: * Myocardial infarction * Unstable angina * Symptomatic congestive heart failure * Serious uncontrolled cardiac arrhythmia * Cerebrovascular accident * Transient ischemic attack * Symptomatic carotid artery or peripheral vascular disease * Deep vein thrombosis * Significant thromboembolic event Pulmonary * No pulmonary embolism within the past 6 months Gastrointestinal * No history of gastrointestinal (GI) bleeding * No history of peptic ulcer disease * No active GI bleeding Other * Not pregnant or nursing * No known hypersensitivity to aspirin, NSAIDs, or sulfonamides * No currently active second malignancy other than nonmelanoma skin cancer * Patients are not considered to have a currently active malignancy if they have completed therapy and are considered by their physician to be at less than 30% risk of relapse PRIOR CONCURRENT THERAPY: Biologic therapy * No prior immunotherapy for NSCLC Chemotherapy * No prior chemotherapy for NSCLC * No other concurrent chemotherapy Endocrine therapy * See Disease Characteristics * No concurrent chronic oral steroids * Concurrent episodic steroids for antiemetic purposes allowed * No concurrent hormonal therapy * Concurrent inhaled steroids allowed when medically indicated * Concurrent megestrol for appetite stimulation is allowed Radiotherapy * See Disease Characteristics * At least 2 weeks since prior radiotherapy and recovered Surgery * See Disease Characteristics * At least 2 weeks since prior surgery and recovered Other * No prior systemic treatments for NSCLC * No other concurrent investigational therapy * At least 1 week since prior nonsteroidal anti-inflammatory drugs (NSAIDs), including any of the following: * Rofecoxib * Choline magnesium trisalicylate * Ibuprofen * Naproxen * Etodolac * Oxaprozin * Diflunisal * Nabumetone * Tolmetin * Valdecoxib * No concurrent NSAIDs * No concurrent chronic aspirin * Concurrent aspirin no greater than 325 mg/day is allowed * No concurrent fluconazole * No concurrent leukotriene antagonists (e.g., zafirlukast, montelukast, or pranlukast)