The pulmonologist is the focal point for the diagnosis and staging of lung cancer. Accurate staging is imperative because of the implications that stage has on different treatment modalities and subsequently on survival. Early stage lung cancer is treated with surgery alone. For the majority of patients, locally advanced lung cancer with involvement of the mediastinum is treated with chemotherapy combined with radiotherapy. Finally, metastatic lung cancer is treated with chemotherapy alone. Accurate staging not only allows for the choice of the most appropriate therapy, it predicts survival. For example, early stage lung cancer treated with surgical resection has a 5-year survival on the order of 60 to 75%. However, with metastasis to the mediastinum (stage IIIA disease), the 5-year survival drops to approximately 17%.