Conduct a prospective study to confirm the value of circulating tumor DNA and its aberrant methylation in longitudinal monitoring of surgical lung cancer patients.

Studies have already demonstrated the feasibility of circulating tumor DNA as a surrogate to reveal tumor mutation status in lung cancer patients and a few researches have shown the potential ability of using circulating tumor DNA in surveillance. However, no study focused on the value of methylation status of circulating tumor DNA in the surveillance and no strict prospective study has been performed in surgical lung cancer patients.

The investigators plan to analyze the dynamic change of circulating tumor DNA and its methylation status longitudinally from preoperation to long term follow-up in surgical lung cancer patients, and compare assessment value between circulating tumor DNA detection with methylation , traditional imaging examinations and traditional blood tumor markers in the monitoring process.

Inclusion Criteria:

Aged 18 to 80 years

• Lung cancer was suspected preoperatively.
• Received curative surgical therapy
• No malignant tumor history within the past 5 years
• No being received any treatment prior to resection
• Patients must have given written informed consent

Exclusion Criteria:

• The pulmonary nodule is pure ground glass opacity
• Unable to comply with the study procedure
• The postoperative pathology is not NSCLC.
• Unqualified blood samples

Histologically confirmed lung cancer patients who received surgical therapy