Gefitinib and Celecoxib in Treating Patients With Refractory Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed non-small cell lung cancer (NSCLC) * Progression of disease during platinum-based (cisplatin or carboplatin) chemotherapy or within 3 months of completing chemotherapy * Treatment with other agents since prior platinum-based chemotherapy allowed * Measurable disease * Target lesions within a prior radiation field must have documented evidence of progression at least 8 weeks after the completion of radiotherapy * No active brain or leptomeningeal metastases * Treated brain metastases allowed at least 4 weeks after the completion of appropriate therapy PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 8 g/dL Hepatic * Bilirubin no greater than upper limit of normal (ULN) * AST/ALT no greater than 2.5 times ULN (if alkaline phosphatase is no greater than ULN) * Alkaline phosphatase no greater than 5 times ULN (if AST and ALT are greater than ULN) * No history of chronic hepatitis Renal * Creatinine no greater than 1.5 times ULN Cardiovascular * No active thromboembolic event within the past 4 weeks * No uncontrolled congestive heart failure * No uncontrolled angina * No myocardial infarction and/or stroke within the past 6 months Pulmonary * No evidence of clinically active interstitial lung disease Gastrointestinal * No history of gastrointestinal bleeding within the past 6 months * No history of peptic ulcer disease Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Must weigh at least 110 pounds (50 kg) * HIV negative * No allergy to sulfonamides * No allergy to any NSAID, including celecoxib * No known severe hypersensitivity to gefitinib or any of its excipients * No other malignancy within the past 3 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix * No history of dementia, active psychiatric disorder, or any other condition that would preclude study compliance * No other concurrent serious medical condition PRIOR CONCURRENT THERAPY: Biologic therapy * No prior epidermal growth factor receptor inhibitor * No concurrent biologic therapy Chemotherapy * See Disease Characteristics * More than 2 weeks since prior chemotherapy Endocrine therapy * Not specified Radiotherapy * Recovered from prior radiotherapy Surgery * Recovered from prior surgery Other * Recovered from prior therapy * More than 2 weeks since prior investigational therapy * More than 1 week since prior fluconazole * More than 30 days since prior participation in another investigational agent clinical trial * More than 30 days since prior chronic nonsteroidal anti-inflammatory drugs (NSAIDs), including celecoxib or rofecoxib * No prior gefitinib * No prior cyclooxygenase-2 (COX-2) inhibitor or another clinical trial for NSCLC * No other concurrent NSAIDs * Concurrent aspirin allowed (not to exceed 325 mg/day) * No other concurrent COX-2 inhibitors * No concurrent lithium * No concurrent fluconazole * No concurrent use of any of the following: * Phenytoin * Carbamazepine * Barbiturates * Rifampin * Phenobarbital * Hypericum perforatum