PRIOR CONCURRENT THERAPY: Biologic therapy: No prior biologic therapy for non-small cell lung cancer No concurrent biologic therapy to measurable or evaluable lesions Chemotherapy: No prior systemic chemotherapy for non-small cell lung cancer Endocrine therapy: No concurrent hormonal therapy to measurable or evaluable lesions Radiotherapy: At least 3 weeks since prior radiotherapy and recovered No concurrent radiotherapy to measurable lesions Palliative radiation to small field nonmeasurable sites of disease (painful bony metastases) allowed Surgery: At least 3 weeks since surgery (thoracic or other major surgeries) and recovered