Chemotherapy Plus Radiation Therapy in Treating Patients With Stage I, Stage II, or Stage III Non-small Cell Lung Cancer That Cannot Be Surgically Removed

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Radiation therapy used high-energy x-rays to damage tumor cells. It is not yet know whether chemotherapy followed by radiation therapy is more effective than chemotherapy given with radiation therapy for non-small cell lung cancer. PURPOSE: Randomized phase III trial to compare the effectiveness of two different regimens of chemotherapy and radiation therapy in treating patients who have unresectable stage I, stage II, or stage III non-small cell lung cancer.