Randomized phase III trial to determine the effectiveness of carboxyamidotriazole in treating patients who have stage III or stage IV non-small cell lung cancer. Chemotherapeutic agents are modestly effective for the treatment of advanced lung cancer, with rapid tumor relapse and growth even after initial response to therapy. It is not yet known whether carboxyamidotriazole is more effective than no further treatment after standard chemotherapy for non-small cell lung cancer.