CtDNA detection is a noninvasive detection method, and 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. This project is to study the role of ctDNA dynamic monitoring of stage I NSCLC by NGS technique to verify the prognostic predictive effect of ctDNA .

CtDNA detection as a noninvasive detection method, can truly reflect the real tumor tissue gene mutation map and frequency, is the evaluation of therapeutic effect and the important monitoring indicators of clinical follow-up after treatment. 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 ctDNA dynamic monitoring of stage I non-small cell lung cancer (NSCLC) was performed by the second generation gene sequencing (NGS) technique to verify the prognostic predictive effect of ctDNA in stage I NSCLC patients without radiotherapy and targeted therapy.

Inclusion Criteria:

• Postoperative histopathological diagnosis of TNM stage IA / IB NSCLC with R0 resection;
• No adjuvant chemotherapy, radiotherapy, targeted drug therapy or biotherapy after surgery;

General selection criteria:

• Men or women of age ≥18 years and <75 years old;
• 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 I Non-small Cell Lung Cancer (NSCLC) without Postoperative radiotherapy and chemotherapy

The investigators will not share IPD to other researchers until initial experimental conclusions is reached.