Cisplatin, Vinorelbine, and Radiation Therapy in Treating Patients With Stage III Non-Small Cell Lung Cancer That Cannot Be Removed By Surgery

RATIONALE: Drugs used in chemotherapy, such as cisplatin and vinorelbine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. It is not yet known whether giving combination chemotherapy followed by radiation therapy is more effective than giving combination chemotherapy together with radiation therapy followed by more chemotherapy in treating non-small cell lung cancer. PURPOSE: This randomized phase III trial is studying combination chemotherapy followed by radiation therapy to see how well it works compared to combination chemotherapy combined with radiation therapy followed by more chemotherapy in treating patients with stage III non-small cell lung cancer that cannot be removed by surgery.