Study subject:
Inclusion criteria 1. Patients with clinical stage 1 to 3a non-small lung cancer 2. Patients with a resectable suspicious pulmonary lesion which is difficult for pre-operation tissue prove or refused for pre-operation biopsy 3. Received curative intended tumor resection Exclusion criteria
1. Small cell lung cancer component which identified in pathology
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 pathology confirmation
5. Patients who received neoadjuvant therapy
Data collection:
medical record review and blood sampling for circulating tumor cell purification
Timing of blood sampling:
a.Pre-operation, post-operation, post-operation day 1, post-operation day 3 b regular OPD surveillance (3 month-interval) for 3 years
Blood sampling: 20 ml blood that withdrawn from a peripheral vein
Circulating tumor cell purification: two-step procedure
1. cell isolation: centrifugation, isolated karyocyte \> 10 micrometer
2. negative selection: wash out RBC, WBC depletion
3. positive selection: purify circulating tumor cell (karyocyte which presented CD 45 negative, Epi-CAM positive, diameter greater 10 micrometer
Result analysis:
Combine the medical record to analyze the relationship between circulating tumor cells and disease relapse
