From literature review, circulating tumor cell was demonstrated its possible role in disease relapse. It was rare nit could be identified in all lung cancer patients. In addition, circulating tumor cell usual aggregate to form circulating tumor micro-emboli and caused distant metastases. Therefore, circulating tumor cell could play a role in detect disease relapse and appropriate treatment could be given more earlier and further prolong patients' survival. However, the detail clinical significance of circulating tumor still remain unknown. The aim of this study was evaluate the clinical significance, including present timing, numbers, and correlation to disease relapse, of circulating tumor cell in lung cancer patients. Investigators want to clarify the clinical significance between circulating tumor cell and clinical presentation of lung cancer in order to establish new prediction model and improve lung cancer patients' survival.

Lung cancer was a major cause of cancer-related death worldwide. According to statistical data from Ministry of Health and Welfare, the incidence of lung cancer related death was 25.5 per 100,000 population. According to NCCN guideline, the standard treatment for patients with resectable disease is anatomic resection and mediastinal lymph node dissection. The current prognostic system, TNM system, was based of patho-histologic characteristics and this system provide the most important information about disease-free and overall survival for corresponding disease severity. According to investigators previous studies, investigators've identified risk factors for all lung cancer patients with resectable disease and poor prognostic factors in different TNM stage. Investigators could utilized factors that designed for all patients as an initial survey and further subgroup patients into high or low risk for relapse in subsequent stratification that utilized grading system in different TMN stage. If investigators could identified high risk patients, more aggressive treatment and follow up program may decreased risk of disease relapse and prolong patient survival.

From literature review, circulating tumor cell was demonstrated its possible role in disease relapse. It was rare nit could be identified in all lung cancer patients. In addition, circulating tumor cell usual aggregate to form circulating tumor micro-emboli and caused distant metastases. Therefore, circulating tumor cell could play a role in detect disease relapse and appropriate treatment could be given more earlier and further prolong patients' survival. However, the detail clinical significance of circulating tumor still remain unknown. The aim of this study was evaluate the clinical significance, including present timing, numbers, and correlation to disease relapse, of circulating tumor cell in lung cancer patients. Investigators want to clarify the clinical significance between circulating tumor cell and clinical presentation of lung cancer in order to establish new prediction model and improve lung cancer patients' survival.

Inclusion Criteria:

1. Non-small cell lung cancer patients with stage I to III

2. Patients with resectable suspicious pulmonary malignant lesion

   1. no pre-operation diagnosis ( patients refused biopsy or difficult for biopsy)
   2. image survey showed clinical stage I to III

Exclusion Criteria:

1. Final pathology coexisted with small cell lung cancer component
2. Patients who presented as stage IIIb or IV.
3. Not received curative intended surgery due to multi-comorbidities.
4. Patients who presented in tumor seeding or positive resection in the final pathology
5. Patients who received neoadjuvant therapy.

Patients with a resectable malignant or suspicious malignant pulmonary lesion