摘要
Lung cancer is the most common cancer worldwide. In the United States, it causes more cancer-related deaths than the next four causes （breast cancer, prostate cancer, colon cancer, and pancreatic cancer） of cancer-related mortality combined （1）. About 30% of people have already progressed to stage III lung cancer and 40% to stage IV at the time they are diagnosed （2）. Although chest X-ray and sputum cytology, when applied in health check-ups, can identify some relatively small tumors, they are not able to lower the overall mortality （3）. More recently,
Lung cancer is the most common cancer worldwide. In the United States, it causes more cancer-related deaths than the next four causes （breast cancer, prostate cancer, colon cancer, and pancreatic cancer） of cancer-related mortality combined （1）. About 30% of people have already progressed to stage III lung cancer and 40% to stage IV at the time they are diagnosed （2）. Although chest X-ray and sputum cytology, when applied in health check-ups, can identify some relatively small tumors, they are not able to lower the overall mortality （3）. More recently,
