The conception of molecular residual disease (MRD) extending from hematologic tumor to solid tumors. Evidences supporting MRD evaluation for lung cancer by liquid biopsy has gradually accumulated, especially circulating tumor DNA (ctDNA). In this observational study, the investigators prospectively enroll stage I-IIIA non-small cell lung cancer (NSCLC) patients who underwent complete resection. Preoperative blood sample, tumor tissue and dynamic postoperative blood samples are collected continuously for MRD detection. This study aim to explore the prognostic value of MRD for stage I-IIIA NSCLC patients after complete resection.

There will be a rapid surge in research about molecular residual disease (MRD) for solid cancer in the near future. However, MRD differed significantly between tumor types and between contexts; there continues to be a considerable lack of awareness and knowledge about using MRD in lung cancer. Hence, this study aims to investigate the value of MRD in NSCLC patients who underwent complete resection. Preoperative blood sample (20ml), tumor tissue and dynamic postoperative blood samples (20ml) are collected continuously for MRD detection. The follow-up was performed once every 3 to 6 months. The primary objective of this study is to assess the prognostic value of MRD for stage I-IIIA NSCLC patients after complete resection.

Inclusion Criteria:

• Diagnosis of histologically confirmed NSCLC (WHO 2015 classification) with resectable (stage I-IIIA) disease.
• Complete resection
• Age ≥18 years at the time of screening
• Capable of giving signed informed consent

Exclusion Criteria:

• Mixed small cell and NSCLC histology
• Rx, R1 or R2 resection
• History of other malignant tumors within 5 years

The pathological diagnosis confirmed stage I-IIIA NSCLC patients who underwent complete resection. No history of other malignant tumors within 5 years.

The IPD could be shared after seeking consent from the corresponding investigator.