OBJECTIVES: I. Compare gemcitabine plus vinorelbine vs standard chemotherapy containing cisplatin in terms of the effect on the quality of life of patients with stage IIIB or IV non-small cell lung cancer. II. Compare the effect of these regimens on the overall survival of these patients. III. Compare the toxic effects of these regimens in these patients. IV. Compare the effect of these regimens on the rate of objective response in these patients.