Previous study showed circulating tumor DNA levels reflect the total systemic tumor burden. Circulating tumor DNA levels should decrease after complete surgery and could be increase as tumor recurrence. Few study investigated the half time of circulating tumor DNA in lung cancer patients that no criterion has been established of how to use it for surveillance.

For lung cancer patients who received surgery, multiple time of plasma will be collected before or after surgery. A series of mutations will be detected in plasma before surgery based on next generation sequencing. The positive mutation will be traced after surgery and in follow up.

Inclusion Criteria:

• Suspected lung cancer before surgery
• No malignant tumor history within the past 5 years
• The pulmonary nodule is not pure ground glass opacity
• Patients must have given written informed consent

Exclusion Criteria:

• Multiple primary lung cancer
• R1,R2 resection
• Histology confirmed not non-small cell lung cancer
• Unqualified blood samples

Histologically confirmed lung cancer patients who received completely tumor resection