Participants will be consented into the study after they are found to meet the study inclusion criteria. The clinical staff will schedule a tissue biopsy and a blood draw for the participant to give NGS(Next-generation Sequencing).One is according to the germline mutation data to screen susceptible gene in SCLC(Small Cell Lung Cancer); two is to explore the extensive consistency detection of blood and tissues in patients with SCLC gene mutation information; three is to conduct dynamic monitoring of blood ctDNA(circulating tumor DNA) in patients with SCLC during treatment, by changing the types of mutations / abundance (for example: the clonal evolution of typical samples analysis) and change of tumor load, , investigating the patients treatment effect , for the significant change of mutations, to study whether it can be used as molecular marker; four is to analyze of the molecular typing of SCLC, according to the clinical and pathological features of patients.

Inclusion Criteria:

• Patients must understand the rigors of the study and provide written informed consent and HIPAA authorization prior to initiation of any study procedures
• Life expectancy > 10 months
• Karnofsky Performance Status ≥ 70
• Diagnosis of histological or cytologically confirmed SCLC,
• Age ≥ 18 years
• Good medical candidate for and willing to undergo a biopsy or surgical procedure to obtain tissue, which may or may not be part of the patient's routine care for their malignancy.

Exclusion Criteria:

• Poor compliance, reluctant to undergo research medication, or follow-up.
• Tumor inaccessible for biopsy
• It is currently included in clinical trials of other drugs, or at the same time, into other medical studies that are considered incompatible with the study.
• It has a history of other cancers, unless the cancer is completely relieved and has not been treated for more than 3 years.

SCLC