Gefitinib With or Without Carboplatin and Paclitaxel in Treating Older Patients With Unresectable or Metastatic Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed non-small cell lung cancer (NSCLC) * Metastatic or unresectable disease * Measurable disease * At least 1 lesion at least 2.0 cm * Disease must be completely outside prior radiotherapy port OR documented disease progression since the completion of radiotherapy * No meningeal carcinomatosis * No untreated brain metastases * Current metastatic CNS disease must have been treated and clinically stable for at least 2 weeks prior to study chemotherapy * No potentially curative treatment options available (e.g., chemotherapy with surgery or radiotherapy) PATIENT CHARACTERISTICS: Age * 65 and over Performance status * ECOG 0-2 Life expectancy * At least 12 weeks Hematopoietic * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 10.0 g/dL Hepatic * Bilirubin no greater than 2.0 mg/dL * No uncontrolled hepatic disease Renal * Creatinine no greater than 2 times upper limit of normal * No uncontrolled renal disease Cardiovascular * No uncontrolled cardiac disease Pulmonary * No clinically active interstitial lung disease * Asymptomatic, chronic stable radiographic changes allowed * No uncontrolled respiratory disease Other * Fertile patients must use effective contraception * Able and willing to complete questionnaires alone or with assistance * No known hypersensitivity to gefitinib or any of its excipients * No active infection within the past 2 weeks * No other prior malignancy within the past 5 years except basal cell skin cancer * No grade 2 or greater peripheral neuropathy (CTC v2.0) * No uncontrolled diabetes mellitus (for patients receiving study chemotherapy) * No dysphagia or inability to swallow intact capsules * No significant medical condition that would preclude study treatment or follow-up * No severe or uncontrolled systemic disease PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * See Disease Characteristics * No prior chemotherapy for metastatic NSCLC Endocrine therapy * Concurrent steroids allowed provided the dose is not changed Radiotherapy * See Disease Characteristics * At least 3 weeks since prior radiotherapy and recovered * No prior radiotherapy to more than 25% of marrow-containing skeleton * No concurrent radiotherapy (including palliative) Surgery * See Disease Characteristics * At least 3 weeks since prior major surgery * No surgery within 7 days after study participation Other * More than 30 days since prior non-FDA approved investigational drugs * No concurrent oral retinoids * No concurrent CYP3A4-inducing agents, including the following: * Carbamazepine * Oxcarbazepine * Modafinil * Ethosuximide * Griseofulvin * Nafcillin * Phenobarbital * Phenylbutazone * Phenytoin * Primidone * Rifampin * Hypericum perforatum (St. John's wort) * Barbiturates * Sulfinpyrazone * No concurrent drugs that cause sustained elevation of gastric pH (≥ 5) * No concurrent antacids within 4 hours before, during, and within 4 hours after gefitinib administration * No concurrent itraconazole, fluconazole, ketoconazole, or erythromycin