The second generation of high-throughput gene sequencing (NGS) is an important means of detecting the tumor DNA and circulating tumor DNA (ctDNA), which can detect trace ctDNA from smaller plasma samples. This project is chiefly to study the role of ctDNA dynamic monitoring of stage IIA to IIIA NSCLC by NGS technique to verify the prognostic predictive effect of ctDNA. And the investigators also wander the concordance of lung cancer related genes mutation map and frequency between primary tumors and infiltrated regional lymph nodes.

In the NGS era, ctDNA detection can truly reflect the real tumor tissue gene mutation map and frequency. It becomes the evaluation of therapeutic effect and the important monitoring indicators of clinical follow-up after surgery and adjuvant chemotherapy. The second generation of high-throughput gene sequencing (NGS) is an important means of detecting ctDNA, which can detect trace ctDNA from smaller plasma samples. The DNA dynamic monitoring of stage II to IIIA non-small cell lung cancer (NSCLC) was performed by the NGS technique to verify prognostic predictive effect of ctDNA in stage IIA to IIIA NSCLC patients after operation. The lung cancer related genes mutation map and frequency between primary tumors and infiltrated regional lymph nodes seems not exactly consistent. In this study, the investigators will compare the lung cancer related genes mutation map and frequency between primary tumors, bloodstream and infiltrated lymph node by the NGS technique.

Inclusion Criteria:

• Postoperative histopathological diagnosis of TNM stage IIA to IIIA NSCLC with R0 resection;
• No previous chemotherapy, radiotherapy, surgery or biological therapy for lung cancer；
• Eastern Cooperative Oncology Group (ECOG) behavior status score 0 to 1.

Exclusion Criteria:

• Patients with other cancers other than NSCLC within five years prior to this study;
• Who can not get enough tumor histological specimens (non-cytological) for analysis;
• Human immunodeficiency virus (HIV) infection;
• NSCLC mixed with patients with small cell lung cancer;
• Pregnant or lactating women;
• There is a clear history of neurological or mental disorders, including epilepsy or dementia;
• Conditions that investigators think is not suitable for inclusion.

Patients With Stage IIA to IIIA Non-small Cell Lung Cancer (NSCLC) with R0 resection.