The objective of the study was to compare the value of routine gene testing and next-generation sequencing (NGS) in detecting gene mutations of small specimens obtained by endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) and get the knowledge of how many EBUS-TBNA samples were adequate for NGS.

Some gene mutations can direct individualized treatment. The routine gene testing of EGFR, ROS1 and ALK is direct sequencing, Reverse transcription quantitative real-time polymerase chain reaction (RT-QPCR) and fluorescent in situ hybridization (FISH) or immunohistochemistry (IHC). Next-generation sequencing (NGS) is a new technique, which is more sensitive than routine techniques. So we decided to compare the value of gene testing between routine method and NGS in EBUS-TBNA specimens and get the knowledge of how many EBUS-TBNA samples were adequate for NGS.

The study was designed as a prospective and single center study. Seventy patients will be enrolled into the study and the clinical data of the patients, including his smoke history, cancer history, occupation exposure and so on, will be collected and recorded in a case report form. For the patients recruited in the study, the lymph nodes suspected to be malignant will be obtained by EBUS-TBNA. Samples will be sent to Pathology Department of Shanghai Chest Hospital and will be processed with paraffin-embedded, and for those diagnosed with nonsquamous NSCLC, routine gene testing of EGFR, ROS1 and ALK will be performed. And the rest tissues will be extracted with DNA and performed gene mutations using NGS for these qualified DNA samples.

Inclusion Criteria:

1. Patients who are suspected with nonsquamous non-small cell lung cancer according to the clinical, lab examination and imaging data and had never been diagnosed as primary lung cancer before will be enrolled into the study.
2. The clinical stage of the patients should be in stage IIIA-IV judged by the imaging data and can't receive surgery initially.

4. There exist at least one lesions that can be obtained by EBUS-TBNA.

Exclusion Criteria:

1. The patient is highly suspected to benign lesion, small cell lung cancer and squamous cell carcinoma according to the clinical data.
2. Surgery was considered to be the primary treatment.
3. Patients who are diagnosed with lung cancer and received treatment with drugs or recurrent with lung cancer will be excluded.
4. Severe cardiopulmonary dysfunction and other indications that can't tolerate bronchoscopy.