Surgery, Gemcitabine, Cisplatin, and Radiation Therapy in Treating Patients With Stage II or Stage III Non-Small Cell Lung Cancer

RATIONALE: Drugs used in chemotherapy, such as gemcitabine and cisplatin, 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) together with radiation therapy after surgery may kill any tumor cells that remain after surgery. PURPOSE: This phase II trial is studying how well surgery followed by gemcitabine, cisplatin, and radiation therapy works in treating patients with stage II or stage III non-small cell lung cancer.