肺癌是目前世界上最常见的恶性肿瘤之一,由于早期肺癌往往缺乏临床症状,病人就诊时发现的肺癌多已是中晚期,五年存活率仅为12～15%。早期肺癌(Ⅰ期),特别其直径小于2cm的肺癌往往无远处及淋巴结转移,手术切除有良好的预后,五年存活率可达70%。然而常规检查方法检出早期肺癌仅为20%。多年来国 Lung cancer is one of the most common malignancies in the world. Because early stage lung cancer often lacks clinical symptoms, the lung cancer found at the time of the patient’s visit is mostly in the middle and late stages. The five-year survival rate is only 12 to 15%. Early stage lung cancer (Phase I), especially lung cancer less than 2cm in diameter, often has no distant metastasis and lymph node metastasis. Surgical resection has a good prognosis and the five-year survival rate can reach 70%. However, routine examination methods detect only 20% of lung cancers. Over many years