Gemcitabine and Oxaliplatin as Second-Line Therapy in Treating Patients With Stage III or Stage IV Non-Small Cell Lung Cancer

RATIONALE: Drugs used in chemotherapy, such as gemcitabine and oxaliplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells. PURPOSE: This phase II trial is studying how well giving gemcitabine together with oxaliplatin works as second-line therapy in treating patients with stage III or stage IV non-small cell lung cancer.