Circulating tumor cells (CTCs), which shed from the primary tumor into the vasculature or lymphatics, can be regarded as a new prognostic factors of metastatic process. Thus far, CTCs-detection technologies can be divided into epithelial cell adhesion molecule (EpCAM)-based detection methods, e.g., the widely used CellSearch® and Adnatest®,and EpCAM-independent detection methods, e.g., ISET® and ScreenCell®. Herein, the investigators used a newly established approach, i.e., CanPatrolTM to detect CTCs in early stage lung Adenocarcinoma cases.