RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. It is not yet known which combination chemotherapy regimen is more effective in treating advanced non-small cell lung cancer.

PURPOSE: Randomized phase III trial to compare the effectiveness of three different combination chemotherapy regimens in treating patients who have advanced non-small cell lung cancer.

OBJECTIVES: I. Compare the overall survival between paclitaxel/cisplatin (arm I), gemcitabine/cisplatin (arm II), and paclitaxel/gemcitabine (arm III) in patients with advanced non-small cell lung cancer. II. Determine the response rate, duration of response, progression-free survival, toxicity, and quality of life of these patients randomized in these three treatment arms.

OUTLINE: This is randomized, multicenter study. Patients are stratified according to performance status (0-1 vs 2) and stage of disease (locally advanced vs metastatic). Patients are randomized to receive paclitaxel IV over 3 hours on day 1 followed by cisplatin IV on day 1 every 3 weeks (arm I), gemcitabine IV over 30-60 minutes on days 1 and 8 and cisplatin IV on day 1 every 3 weeks (arm II), or paclitaxel IV over 3 hours on day 1 followed by gemcitabine IV over 30-60 minutes on days 1 and 8 every 3 weeks (arm III). Patients receive at least 2 courses of treatment. In the absence of unacceptable toxicity and disease progression, patients may receive up to 6 courses of treatment. Quality of life is assessed before, during, and at the end of treatment, then every 6 weeks until disease progression, and then every 3 months until death. Patients are followed every 6 weeks until disease progression, then every 3 months until death.

PROJECTED ACCRUAL: A total of 450 patients (150 patients per arm) will be accrued into this study over 36 months.

DISEASE CHARACTERISTICS: Histologically confirmed advanced non-small cell lung cancer that is progressive within 2 months prior to study entry Stage IIIB due to malignant pleural effusion or supraclavicular lymph node involvement only Stage IV At least 1 bidimensionally or unidimensionally measurable target lesion Brain metastases or leptomeningeal disease that have been treated with radiotherapy, is stable without medications (e.g., steroids), and asymptomatic are allowed

PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: WHO 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Prothrombin time less than 1.5 times normal Hepatic: Bilirubin no greater than 1.25 times upper limit of normal (ULN) (no greater than 2.5 times ULN if due to liver metastases) AST or ALT less than 3 times ULN (no greater than 5 times ULN if due to liver metastases) Renal: Creatinine clearance at least 60 mL/min Cardiovascular: No uncontrolled cardiac disease, sign of cardiac failure, or rhythm disturbances requiring medication No myocardial infarction in the past 3 months Neurological: No preexisting motor or sensory neurotoxicity of grade 2 or greater Other: No active uncontrolled infection Not a poor medical risk due to nonmalignant disease No secondary primary malignancy in the past 5 years (excluding melanoma, breast cancer, and hypernephroma) except carcinoma in situ of the cervix or adequately treated basal cell carcinoma of the skin No psychological condition that might hamper compliance in this study Not pregnant Effective contraception required of all fertile patients during and for 3 months after study

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunotherapy No concurrent colony stimulating factor except for secondary prophylaxis in case of infection and severe neutropenia No concurrent immunotherapy Chemotherapy: No prior chemotherapy for advanced disease, including intracavitary chemotherapy At least 1 year since prior neoadjuvant or adjuvant chemotherapy No concurrent chemotherapy Endocrine therapy: See Disease Characteristics No concurrent hormonal agents (except corticosteroids for antiemetic prophylaxis) Radiotherapy: Prior radiotherapy should not include all target lesions for evaluation At least 4 weeks since prior radiotherapy Concurrent palliative radiotherapy allowed if indicator lesion is outside of radiation field Surgery: Not specified