Lung cancer is one of the most common malignancies worldwide and the leading cause of cancer-related deaths in Western countries. Standard treatment for patients with good performance status (PS) stage IIIB/IV NSCLC currently includes a two-drug platinum-based chemotherapy regimen, but optimum treatment for elderly patients is less well-defined due to platinum related toxicities. Several drugs with novel mechanisms of action and significant activity in NSCLC have been developed; including docetaxel and gemcitabine that are also active in patients previously treated with cisplatin-based regimens and have a more favorable toxicity profile. The more favorable toxicity profile of docetaxel and gemcitabine supports its use as first-line chemotherapy, especially in patients with severe comorbidities as elderly patients. To improve the therapeutic index of this combination, the investigators performed a study with biweekly gemcitabine and docetaxel in elderly patients.