OBJECTIVES: I. Determine the activity and toxicities of gemcitabine in elderly patients with non-small cell lung cancer. II. Determine the activity and toxicity of the combination of gemcitabine and vinorelbine in these patients. III. Compare the survival rate and quality of life of these patients treated with combination chemotherapy versus single agent chemotherapy. IV. Compare objective response and time to progression of these patients treated with these chemotherapy regimens. V. Compare the toxicities of these three regimens in these patients. VI. Compare the number of hospitalizations, palliative radiation therapies, antibiotic therapies, corticosteroid therapies, analgesic therapies, and hematopoietic growth factor therapies needed for these patients treated with these chemotherapy regimens.