Cisplatin Plus Vinorelbine With or Without Tirapazamine in Treating Patients With Stage IIIB or Stage IV Non-Small Cell Lung Cancer

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. It is not yet known if cisplatin and vinorelbine are more effective with or without tirapazamine in treating non-small cell lung cancer PURPOSE: Randomized phase III trial to compare the effectiveness of cisplatin plus vinorelbine with or without tirapazamine in treating patients who have stage IIIB or stage IV non-small cell lung cancer.